Date: Mon, 27 Jan 2014 00:04:14 -0500
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There are 2 messages totalling 1193 lines in this issue.
Topics of the day:
1. Reference for typical SNRs is public spaces (2)
Date: Sat, 25 Jan 2014 08:32:37 -0800
From: Pierre Divenyi <pdivenyi@xxxxxxxxxxxxxxxxxx>
Subject: Re: Reference for typical SNRs is public spaces
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I agree with Bill except for one (crucial) assumption: in a cocktail-party
situation the noise is not stationary (although, as Jont Allen once
suggested, adding talkers to the babble will make it approach stationarity)=
.
So, the 0.5 dB SNR is workable in a broad statistical sense and would have
to be adjusted almost on a case-by-case basis.
-Pierre
From: "Richard F. Lyon" <dicklyon@xxxxxxx>
Reply-To: "Richard F. Lyon" <dicklyon@xxxxxxx>
Date: Friday, January 24, 2014 at 10:16 PM
To: <AUDITORY@xxxxxxxxxxxxxxx>
Subject: Re: [AUDITORY] Reference for typical SNRs is public spaces
I think Bill's point, which I agree with, is that the SNR is not determined
by the noise in the space as much as it is by people trying to communicate.
The SNR that he estimates is not "in the space", but rather "at the ears of
the listener" when the talker is trying to communicate to that particular
listener, above the noise. Other people trying to communicate to different
listeners make noise for this one. The SNR is therefore roughly constant,
somewhere near 0 dB, almost anywhere that's not too quiet.
For me, it's a little higher, after I make people speak up.
Dick
On Fri, Jan 24, 2014 at 1:51 PM, Bill Woods <Bill_Woods@xxxxxxxxxxx> wrote:
> Dear List,
> =20
> Since we=B9re assuming Andy is asking about speech-to-noise ratio when refe=
rring
> to SNR in public spaces, I wondered if the question couldn=B9t be answered =
by
> back-of-the-envelope calculations using some assumptions and articulation
> index theory (AI).
> =20
> It turned out there was quite a long list of assumptions behind the
> calculation (see below), but the resultant simple calculation yielded a S=
NR of
> 0.5 dB, which is quite in line with the values other posters have indicat=
ed
> may actually be present. Two other facts became apparent as I did this,
> however, and further motivate my posting.
> =20
> First, the long list of assumptions makes apparent the long list of influ=
ences
> on the SNR in such a situation. These influences need to be characterized=
in
> any attempt to generalize from SNR measurements in a given scenario, a fa=
ct
> other posters have alluded to.
> =20
> Second, it is important to note that much work has been done recently to =
model
> or empirically characterize these influences on speech intelligibility, a=
nd
> that, while the models may require more computational power than found on=
the
> back of an envelope, they are no problem to execute on current laptop
> computers. The implication is that it should not be very difficult to
> determine a reasonably-accurate distribution of SNRs over wide variation =
in
> the assumed listening scenario without any measurements.
> Cheers,
> Bill
> =20
> Bill Woods, PhD
> Principal Research Scientist | Starkey Hearing Research Center
> 2150 Shattuck Ave. | Suite 408 | Berkeley, CA 94704-1345
> T: 510-845-4876 x 14 <tel:510-845-4876%C2%A0x%C2%A014>
> starkey.com <http://www.starkey.com/> | starkeyresearch.com
> <http://www.starkeyresearch.com> | map
> <http://maps.google.com/maps?q=3D2150+Shattuck+Avenue,+Berkeley,+CA+94704&h=
l=3Den&
> ll=3D37.869941,-122.268219&spn=3D0.028152,0.038066&sll=3D37.86923,-122.273197&s=
spn=3D0
> .056305,0.076132&z=3D15> | email <mailto:william_woods@xxxxxxxxxxx>
> =20
> The assumptions are:
> 1. Talkers have no hearing loss and no cognitive loss.
> 2. The talkers are facing each other and speaking in their =B3mother tongue=
=B2.
> 3. We know the percent-correct (%C) targeted by the talkers and it is les=
s
> than 100% (it=B9s a challenging environment).
> 4. We know the nature of the speech in such a conversation, from a low-co=
ntext
> vs. high-context perspective.
> 5. The talkers are within their critical distance (i.e., ignore reverbera=
tion
> of talkers=B9 speech).
> 6. We know the long-term spectral shape of speech at the eardrums.
> 7. We know the long-term spectral shape of noise at the eardrums.
> 8. The noise is stationary.
> 9. The noise is diffuse.
> 10. The diffuse noise in combination with diotic direct-wave target speec=
h
> generates the equivalent of an =B3internal=B2 wideband binaural SNR improveme=
nt of
> ~1.0 dB over monaural listening.
> 11. Overall level is not too high (i.e., no =B3roll-over=B2 effect for
> intelligibility has occurred).
> 12. We=B9re not including lip reading.
> =20
> These assumptions allow one to, first, determine the AI needed to achieve=
the
> assumed target %C given the assumed type of speech, and, second, determin=
e the
> SNR required with the assumed spectral shapes to obtain that AI.
> =20
> For instance, assuming talkers want 95%C with =B3unfamiliar sentences=B2 then
> using the polynomial fits from Sherbecoe and Studebaker (JASA 1990) of th=
e
> ANSI S3.5-1969 transfer functions between AI and %C, our talkers would ne=
ed an
> AI of 0.45. If we assume the noise and speech have the same long-term spe=
ctral
> shape then the SNR can be determined from (SNR+12)/30=3D0.45 (staying with =
the
> 1969 AI method), yielding SNR =3D 1.5 dB. Subtracting the binaural SNR
> improvement yields 0.5 dB.
> =20
> From: AUDITORY - Research in Auditory Perception
> [mailto:AUDITORY@xxxxxxxxxxxxxxx] On Behalf Of Andy Sabin
> Sent: Wednesday, January 22, 2014 9:53 AM
>=20
> To: AUDITORY@xxxxxxxxxxxxxxx
> Subject: Reference for typical SNRs is public spaces
> =20
> Hi List,=20
> =20
> Can anyone point me to a reference showing SNRs that are typically observ=
ed in
> public spaces (e.g., restaurants, bars ...etc)? I can find this info for
> overall SPL, but am having a hard time finding it for SNR.
> =20
> Thanks
> Andy Sabin
> =20
>=20
>=20
--B_3473483561_12333698
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<html><head></head><body style=3D"word-wrap: break-word; -webkit-nbsp-mode: s=
pace; -webkit-line-break: after-white-space; color: rgb(0, 0, 0); font-size:=
14px; font-family: Calibri, sans-serif;"><div>I agree with Bill except for =""> one (crucial) assumption: in a cocktail-party situation the noise is not sta=
tionary (although, as Jont Allen once suggested, adding talkers to the babbl=
e will make it approach stationarity). So, the 0.5 dB SNR is workable in a b=
road statistical sense and would have to be adjusted almost on a case-by-cas=
e basis.</div><div><br></div><div>-Pierre</div><div><br></div><span id=3D"OLK_=
SRC_BODY_SECTION"><div style=3D"font-family:Calibri; font-size:11pt; text-alig=
n:left; color:black; BORDER-BOTTOM: medium none; BORDER-LEFT: medium none; P=
ADDING-BOTTOM: 0in; PADDING-LEFT: 0in; PADDING-RIGHT: 0in; BORDER-TOP: #b5c4=
df 1pt solid; BORDER-RIGHT: medium none; PADDING-TOP: 3pt"><span style=3D"font=
-weight:bold">From: </span> "Richard F. Lyon" <<a href="" href="mailto:dicklyon@A">dicklyon@A=
CM.ORG">dicklyon@xxxxxxx</a>><br><span style=3D"font-weight:bold">Reply-To:=
</span> "Richard F. Lyon" <<a href="" href="mailto:dicklyon@xxxxxxx">dicklyon@xxxxxxx">dicklyon@AC=
M.ORG</a>><br><span style=3D"font-weight:bold">Date: </span> Friday, Januar=
y 24, 2014 at 10:16 PM<br><span style=3D"font-weight:bold">To: </span> <<a =
href="" href="mailto:AUDITORY@xxxxxxxxxxxxxxx">AUDITORY@xxxxxxxxxxxxxxx">AUDITORY@xxxxxxxxxxxxxxx</a>><br><=
span style=3D"font-weight:bold">Subject: </span> Re: [AUDITORY] Reference for =""> typical SNRs is public spaces<br></div><div><br></div><div dir=3D"ltr"><div>I =
think Bill's point, which I agree with, is that the SNR is not determined by=
the noise in the space as much as it is by people trying to communicate.&nb=
sp; The SNR that he estimates is not "in the space", but rather "at the ears=
of the listener" when the talker is trying to communicate to that particula=
r listener, above the noise. Other people trying to communicate to dif=
ferent listeners make noise for this one. The SNR is therefore roughly=
constant, somewhere near 0 dB, almost anywhere that's not too quiet.<br><br=
></div>For me, it's a little higher, after I make people speak up.<br><br>Di=
ck<br><br></div><div class=3D"gmail_extra"><br><br><div class=3D"gmail_quote">On=
Fri, Jan 24, 2014 at 1:51 PM, Bill Woods <span dir=3D"ltr"><<a href=""> o:Bill_Woods@xxxxxxxxxxx" target=3D"_blank">Bill_Woods@xxxxxxxxxxx</a>></sp=
an> wrote:<br><blockquote class=3D"gmail_quote" style=3D"margin:0 0 0 .8ex;borde=
r-left:1px #ccc solid;padding-left:1ex"><div><font face=3D"Calibri" size=3D"3"><=
span style=3D"font-size:12pt"><div>Dear List,</div><div><font face=3D"Times New =
Roman"> </font></div><div>Since we’re assuming Andy is asking abo=
ut speech-to-noise ratio when referring to SNR in public spaces, I wondered =
if the question couldn’t be answered by back-of-the-envelope calculati=
ons using some assumptions and articulation index theory (AI). </div><=
div> </div><div>It turned out there was quite a long list of assumption=
s behind the calculation (see below), but the resultant simple calculation y=
ielded a SNR of 0.5 dB, which is quite in line with the values other posters=
have indicated may actually be present. Two
other facts became apparent as I did this, however, and further motivate my=
posting. </div><div> </div><div>First, the long list of assumptions ma=
kes apparent the long list of influences on the SNR in such a situation. The=
se influences need to be characterized in any attempt to generalize from SNR=
measurements in a given scenario, a fact other posters have alluded
to.</div><div> </div><div style=3D"margin-bottom:12pt">Second, it is imp=
ortant to note that much work has been done recently to model or empirically=
characterize these influences on speech intelligibility, and that, while th=
e models may require more computational power than found
on the back of an envelope, they are no problem to execute on current lapto=
p computers. The implication is that it should not be very difficult to dete=
rmine a reasonably-accurate distribution of SNRs over wide variation in the =
assumed listening scenario without
any measurements. </div><div>Cheers,</div><div>Bill</div><div><font face=3D"T=
imes New Roman"> </font></div><table style=3D"width:282.75pt;margin-left:=
5.4pt" width=3D"471"><colgroup><col style=3D"width:282.75pt" width=3D"471"></colgr=
oup><tbody><tr><td><font color=3D"#17365D" face=3D"Arial">Bill Woods, PhD<br><fo=
nt color=3D"#595959"><span style=3D"font-size:10pt">Principal Research Scientist=
| Starkey Hearing Research Center<br>
2150 Shattuck Ave. | Suite 408 | Berkeley, CA =
;94704-1345<br>
T: <a href="" value=3D"+15108454876" targ=
et=3D"_blank">510-845-4876 x 14</a> </span></font></font></td></tr><=
tr><td><font face=3D"Times New Roman"><a href="" href="http://www.starkey.com/" target="_blank">http://www.starkey.com/" target=
=3D"_blank"><font color=3D"blue" face=3D"Arial"><span style=3D"font-size:10pt"><u>st=
arkey.com</u></span></font></a><font color=3D"#0000F6" face=3D"Arial"><span styl=
e=3D"font-size:10pt"> </span></font><font color=3D"#595959" face=3D"Arial"><s=
pan style=3D"font-size:10pt">|</span></font><font color=3D"#0000F6" face=3D"Arial"=
><span style=3D"font-size:10pt"> </span></font><a href="" href="http://www.starke" target="_blank">http://www.starke=
yresearch.com" target=3D"_blank"><font color=3D"blue" face=3D"Arial"><span style=3D"=
font-size:10pt"><u>starkeyresearch.com</u></span></font></a><font color=3D"#00=
00F6" face=3D"Arial"><span style=3D"font-size:10pt"> </span></font><font co=
lor=3D"#595959" face=3D"Arial"><span style=3D"font-size:10pt">|</span></font><font=
color=3D"#0000F6" face=3D"Arial"><span style=3D"font-size:10pt"> </span></fo=
nt><a href="" href="http://maps.google.com/maps?q=3D2150+Shattuck+Avenue,+Berkeley,+CA= +94704&hl=3Den&ll=3D37.869941,-122.268219&spn=3D0.028152,0.038066&= sll=3D37.86923,-122.273197&sspn=3D0.056305,0.076132&z=3D15" target="_blank">http://maps.google.com/maps?q=3D2150+Shattuck+Avenue,+Berkeley,+CA=
+94704&hl=3Den&ll=3D37.869941,-122.268219&spn=3D0.028152,0.038066&=
sll=3D37.86923,-122.273197&sspn=3D0.056305,0.076132&z=3D15" target=3D"_blank=
"><font color=3D"blue" face=3D"Arial"><span style=3D"font-size:10pt"><u>map</u></s=
pan></font></a><font color=3D"#0000F6" face=3D"Arial"><span style=3D"font-size:10p=
t"> </span></font><font color=3D"#595959" face=3D"Arial"><span style=3D"font-=
size:10pt">|</span></font><font color=3D"#0000F6" face=3D"Arial"><span style=3D"fo=
nt-size:10pt"> </span></font><a href="" href="mailto:william_woods@xxxxxxxxxxx">william_woods@xxxxxxxxxxx"=
target=3D"_blank"><font color=3D"blue" face=3D"Arial"><span style=3D"font-size:10pt=
"><u>email</u></span></font></a></font></td></tr><tr><td><font face=3D"Times N=
ew Roman"></font></td></tr><tr><td><font face=3D"Times New Roman"></font></td>=
</tr></tbody></table><div><font face=3D"Times New Roman"> </font></div><d=
iv>The assumptions are:</div><ol style=3D"margin:0;padding-left:36pt"><li>Talk=
ers have no hearing loss and no cognitive loss.</li><li>The talkers are faci=
ng each other and speaking in their “mother tongue”.</li><li>We =
know the percent-correct (%C) targeted by the talkers and it is less than 10=
0% (it’s a challenging environment).</li><li>We know the nature of the=
speech in such a conversation, from a low-context vs. high-context perspect=
ive.</li><li>The talkers are within their critical distance (i.e., ignore re=
verberation of talkers’ speech).</li><li>
We know the long-term spectral shape of speech at the eardrums.</li><li>We =
know the long-term spectral shape of noise at the eardrums.</li><li>The nois=
e is stationary.</li><li>The noise is diffuse.</li><li>The diffuse noise in =
combination with diotic direct-wave target speech generates the equivalent o=
f an “internal” wideband binaural SNR improvement of ~1.0 dB ove=
r monaural listening.</li><li>Overall level is not too high (i.e., no “=
;roll-over” effect for intelligibility has occurred).</li><li>We’=
;re not including lip reading.</li></ol><div><font face=3D"Times New Roman">&n=
bsp;</font></div><div>These assumptions allow one to, first, determine the A=
I needed to achieve the assumed target %C given the assumed type of speech, =
and, second, determine the SNR required with the assumed spectral shapes to =
obtain that AI.</div><div> </div><div>For instance, assuming talkers wa=
nt 95%C with “unfamiliar sentences” then using the polynomial fi=
ts from Sherbecoe and Studebaker (JASA 1990) of the ANSI S3.5-1969 transfer =
functions between AI and %C, our talkers would need an AI of 0.45. If we ass=
ume
the noise and speech have the same long-term spectral shape then the SNR ca=
n be determined from (SNR+12)/30=3D0.45 (staying with the 1969 AI method), yie=
lding SNR =3D 1.5 dB. Subtracting the binaural SNR improvement yields 0.=
5 dB. </div><div><font face=3D"Times New Roman"> </font></div><div>=
<font face=3D"Tahoma"><span style=3D"font-size:10pt"><div class=3D"im"><b>From:</b=
> AUDITORY - Research in Auditory Perception [<a href="" href="mailto:AUDITORY@LISTS">AUDITORY@LISTS=
.MCGILL.CA" target=3D"_blank">mailto:AUDITORY@xxxxxxxxxxxxxxx</a>] <b>On Behal=
f Of </b>Andy Sabin<br></div><b>Sent:</b> Wednesday, January 22, 2014 9:53 A=
M<div class=3D"im"><br><b>To:</b> <a href="" href="mailto:AUDITORY@xxxxxxxxxxxxxxx">AUDITORY@xxxxxxxxxxxxxxx" ta=
rget=3D"_blank">AUDITORY@xxxxxxxxxxxxxxx</a><br><b>Subject:</b> Reference for =""> typical SNRs is public spaces</div></span></font></div><div class=3D"im"><div>=
<font face=3D"Times New Roman"> </font></div><div><font face=3D"Times New R=
oman">Hi List, </font></div><div><font face=3D"Times New Roman"> </f=
ont></div><div><font face=3D"Times New Roman">Can anyone point me to a referen=
ce showing SNRs that are typically observed in public spaces (e.g., restaura=
nts, bars ...etc)? I can find this info for overall SPL, but am having a har=
d time finding it for SNR. </font></div><div><font face=3D"Times New Roma=
n"> </font></div><div><font face=3D"Times New Roman">Thanks</font></div><=
div><font face=3D"Times New Roman">Andy Sabin</font></div><div><font face=3D"Tim=
es New Roman"> </font></div></div></span></font></div></blockquote></di=
v><br></div></span></body></html>
--B_3473483561_12333698--
Date: Sun, 26 Jan 2014 09:54:31 +0000
From: "Smits, Cas" <C.Smits@xxxxxxx>
Subject: Re: Reference for typical SNRs is public spaces
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We used a method to determine the relation between AI/SII and SNR for fluct=
uating noise in a way quite similar to the way Bill proposed (Smits and Fes=
ten, 2013). We found a different relationship between SII and SNR for two-b=
and speech modulated noise compared to steady-state noise (a 2-dB increase =
in SNR for fluctuating noise gives almost the same increase in SII as a 1-d=
B increase in SNR for steady-state noise). This method works well in lab se=
ttings but I think the uncertainties are too large to make reliable predict=
ions for real-life situations. The effects of speaking style, speech materi=
al, talker etc on percentage correct (the speech recognition function) are =
large and the (backward) calculations give large uncertainties in SNR estim=
ates. In situations with fluctuating noise the use of the steady-state nois=
e relationship between SII and SNR could give large errors. With interferin=
g talkers (informational masking) things get even more complicated.
But, coming back to the question, normal-hearing listeners can follow most =
conversations in public spaces with some difficulty (often in situations wi=
th multitalker babble which is very similar to stationairy noise). Thus, SN=
Rs around 0-5 dB SNR sounds plausible...
Cas Smits
Smits C, Festen JM. The interpretation of speech reception threshold data i=
n normal-hearing and hearing-impaired listeners: II. Fluctuating noise.
J Acoust Soc Am. 2013 May;133(5):3004-15
dr.ir. J.C.M. (Cas) Smits, klinisch fysicus-audioloog | Universitair Audiol=
ogisch Centrum | VU medisch centrum
Afdeling KNO-Audiologie | EMGO Institute for Health and Care Research
Secretariaat Audiologie, Postbus 7057, 1007 MB Amsterdam
T (020) 444 09 69 | F (020) 444 09 83 | E c.smits@xxxxxxx<mailto:c.smits@VU=
mc.nl> | W www.AC-VUmc.nl<http://www.AC-VUmc.nl> www.CI-VUmc.nl<http://www=
.CI-VUmc.nl>
Disclaimer
Deze e-mail is vertrouwelijk en alleen bestemd voor de geadresseerde. Als d=
eze e-mail niet voor u bestemd is, wordt u verzocht dit aan de afzender te =
melden, het bericht niet verder te verspreiden en direct te vernietigen. VU=
medisch centrum staat niet in voor de juiste en volledige overbrenging van=
de inhoud van deze e-mail.
Van: AUDITORY - Research in Auditory Perception [mailto:AUDITORY@xxxxxxxxxx=
LL.CA] Namens Pierre Divenyi
Verzonden: Saturday, 25 January, 2014 17:33
Aan: AUDITORY@xxxxxxxxxxxxxxx
Onderwerp: Re: [AUDITORY] Reference for typical SNRs is public spaces
I agree with Bill except for one (crucial) assumption: in a cocktail-party =
situation the noise is not stationary (although, as Jont Allen once suggest=
ed, adding talkers to the babble will make it approach stationarity). So, t=
he 0.5 dB SNR is workable in a broad statistical sense and would have to be=
adjusted almost on a case-by-case basis.
-Pierre
From: "Richard F. Lyon" <dicklyon@xxxxxxx<mailto:dicklyon@xxxxxxx>>
Reply-To: "Richard F. Lyon" <dicklyon@xxxxxxx<mailto:dicklyon@xxxxxxx>>
Date: Friday, January 24, 2014 at 10:16 PM
To: <AUDITORY@xxxxxxxxxxxxxxx<mailto:AUDITORY@xxxxxxxxxxxxxxx>>
Subject: Re: [AUDITORY] Reference for typical SNRs is public spaces
I think Bill's point, which I agree with, is that the SNR is not determined=
by the noise in the space as much as it is by people trying to communicate=
. The SNR that he estimates is not "in the space", but rather "at the ears=
of the listener" when the talker is trying to communicate to that particul=
ar listener, above the noise. Other people trying to communicate to differ=
ent listeners make noise for this one. The SNR is therefore roughly consta=
nt, somewhere near 0 dB, almost anywhere that's not too quiet.
For me, it's a little higher, after I make people speak up.
Dick
On Fri, Jan 24, 2014 at 1:51 PM, Bill Woods <Bill_Woods@xxxxxxxxxxx<mailto:=
Bill_Woods@xxxxxxxxxxx>> wrote:
Dear List,
Since we're assuming Andy is asking about speech-to-noise ratio when referr=
ing to SNR in public spaces, I wondered if the question couldn't be answere=
d by back-of-the-envelope calculations using some assumptions and articulat=
ion index theory (AI).
It turned out there was quite a long list of assumptions behind the calcula=
tion (see below), but the resultant simple calculation yielded a SNR of 0.5=
dB, which is quite in line with the values other posters have indicated ma=
y actually be present. Two other facts became apparent as I did this, howev=
er, and further motivate my posting.
First, the long list of assumptions makes apparent the long list of influen=
ces on the SNR in such a situation. These influences need to be characteriz=
ed in any attempt to generalize from SNR measurements in a given scenario, =
a fact other posters have alluded to.
Second, it is important to note that much work has been done recently to mo=
del or empirically characterize these influences on speech intelligibility,=
and that, while the models may require more computational power than found=
on the back of an envelope, they are no problem to execute on current lapt=
op computers. The implication is that it should not be very difficult to de=
termine a reasonably-accurate distribution of SNRs over wide variation in t=
he assumed listening scenario without any measurements.
Cheers,
Bill
Bill Woods, PhD
Principal Research Scientist | Starkey Hearing Research Center
2150 Shattuck Ave. | Suite 408 | Berkeley, CA 94704-1345
T: 510-845-4876 x 14<tel:510-845-4876%C2%A0x%C2%A014>
starkey.com<http://www.starkey.com/> | starkeyresearch.com<http://www.stark=
eyresearch.com> | map<http://maps.google.com/maps?q=3D2150+Shattuck+Avenue,=
+Berkeley,+CA+94704&hl=3Den&ll=3D37.869941,-122.268219&spn=3D0.028152,0.038=
066&sll=3D37.86923,-122.273197&sspn=3D0.056305,0.076132&z=3D15> | email<mai=
lto:william_woods@xxxxxxxxxxx>
The assumptions are:
1. Talkers have no hearing loss and no cognitive loss.
2. The talkers are facing each other and speaking in their "mother ton=
gue".
3. We know the percent-correct (%C) targeted by the talkers and it is =
less than 100% (it's a challenging environment).
4. We know the nature of the speech in such a conversation, from a low=
-context vs. high-context perspective.
5. The talkers are within their critical distance (i.e., ignore reverb=
eration of talkers' speech).
6. We know the long-term spectral shape of speech at the eardrums.
7. We know the long-term spectral shape of noise at the eardrums.
8. The noise is stationary.
9. The noise is diffuse.
10. The diffuse noise in combination with diotic direct-wave target speech=
generates the equivalent of an "internal" wideband binaural SNR improvemen=
t of ~1.0 dB over monaural listening.
11. Overall level is not too high (i.e., no "roll-over" effect for intelli=
gibility has occurred).
12. We're not including lip reading.
These assumptions allow one to, first, determine the AI needed to achieve t=
he assumed target %C given the assumed type of speech, and, second, determi=
ne the SNR required with the assumed spectral shapes to obtain that AI.
For instance, assuming talkers want 95%C with "unfamiliar sentences" then u=
sing the polynomial fits from Sherbecoe and Studebaker (JASA 1990) of the A=
NSI S3.5-1969 transfer functions between AI and %C, our talkers would need =
an AI of 0.45. If we assume the noise and speech have the same long-term sp=
ectral shape then the SNR can be determined from (SNR+12)/30=3D0.45 (stayin=
g with the 1969 AI method), yielding SNR =3D 1.5 dB. Subtracting the binau=
ral SNR improvement yields 0.5 dB.
From: AUDITORY - Research in Auditory Perception [mailto:AUDITORY@xxxxxxxxx=
ILL.CA] On Behalf Of Andy Sabin
Sent: Wednesday, January 22, 2014 9:53 AM
To: AUDITORY@xxxxxxxxxxxxxxx<mailto:AUDITORY@xxxxxxxxxxxxxxx>
Subject: Reference for typical SNRs is public spaces
Hi List,
Can anyone point me to a reference showing SNRs that are typically observed=
in public spaces (e.g., restaurants, bars ...etc)? I can find this info fo=
r overall SPL, but am having a hard time finding it for SNR.
Thanks
Andy Sabin
--_000_5801ADC15F4A8D4CAC8F4B3195FA6327EF3B322BSPMXMBX32vumcnl_
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ak-word;
-webkit-nbsp-mode: space;-webkit-line-break: after-white-space">
<div class=3D"Section1">
<p class=3D"MsoNormal"><span style=3D"font-size:11.0pt;font-family:"Ca=
libri","sans-serif";
color:#1F497D">We used a method to determine the relation between AI/SII an=
d SNR for fluctuating noise in a way quite similar to the way Bill proposed=
(Smits and Festen,
2013). We found a different relationship between SII and SNR for two-band =
speech modulated noise compared to steady-state noise (a 2-dB increase in S=
NR for fluctuating noise gives almost the same increase in SII as a 1-dB in=
crease in SNR for steady-state noise).
This method works well in lab settings but I think the uncertainties are t=
oo large to make reliable predictions for real-life situations. The effects=
of speaking style, speech material, talker etc on percentage correct (the =
speech recognition function) are
large and the (backward) calculations give large uncertainties in SNR esti=
mates. In situations with fluctuating noise the use of the steady-state noi=
se relationship between SII and SNR could give large errors. With interferi=
ng talkers (informational masking)
things get even more complicated.<o:p></o:p></span></p>
<p class=3D"MsoNormal"><span style=3D"font-size:11.0pt;font-family:"Ca=
libri","sans-serif";
color:#1F497D"><o:p> </o:p></span></p>
<p class=3D"MsoNormal"><span style=3D"font-size:11.0pt;font-family:"Ca=
libri","sans-serif";
color:#1F497D">But, coming back to the question, normal-hearing listeners c=
an follow most conversations in public spaces with some difficulty (often i=
n situations with multitalker
babble which is very similar to stationairy noise). Thus, SNRs around 0-5 =
dB SNR sounds plausible...<o:p></o:p></span></p>
<p class=3D"MsoNormal"><span style=3D"font-size:11.0pt;font-family:"Ca=
libri","sans-serif";
color:#1F497D"><o:p> </o:p></span></p>
<p class=3D"MsoNormal"><span style=3D"font-size:11.0pt;font-family:"Ca=
libri","sans-serif";
color:#1F497D">Cas Smits<o:p></o:p></span></p>
<p class=3D"MsoNormal"><span style=3D"font-size:11.0pt;font-family:"Ca=
libri","sans-serif";
color:#1F497D"><o:p> </o:p></span></p>
<p class=3D"MsoNormal"><span style=3D"font-size:11.0pt;font-family:"Ca=
libri","sans-serif";
color:#1F497D"><o:p> </o:p></span></p>
<p class=3D"MsoNormal"><span style=3D"font-size:11.0pt;font-family:"Ca=
libri","sans-serif";
color:#1F497D">Smits C, Festen JM. The interpretation of speech reception t=
hreshold data in normal-hearing and hearing-impaired listeners: II. Fluctua=
ting noise.<o:p></o:p></span></p>
<p class=3D"MsoNormal"><span style=3D"font-size:11.0pt;font-family:"Ca=
libri","sans-serif";
color:#1F497D">J Acoust Soc Am. 2013 May;133(5):3004-15<o:p></o:p></span></=
p>
<p class=3D"MsoNormal"><span style=3D"font-size:11.0pt;font-family:"Ca=
libri","sans-serif";
color:#1F497D"><o:p> </o:p></span></p>
<p class=3D"MsoNormal"><span style=3D"font-size:11.0pt;font-family:"Ca=
libri","sans-serif";
color:#1F497D"><o:p> </o:p></span></p>
<p class=3D"MsoNormal" style=3D"line-height:12.0pt;mso-line-height-rule:exa=
ctly"><b><span style=3D"font-size:8.0pt;font-family:"Verdana",&qu=
ot;sans-serif";color:#10137D">dr.ir. J.C.M. (Cas) Smits, klinisch fysi=
cus-audioloog</span></b><b><span style=3D"font-size:8.0pt;font-family:ver;c=
olor:#10137D"> </span></b><b><span style=3D"font-size:8.0pt;font-famil=
y:"Verdana","sans-serif";color:#10137D">|
Universitair Audiologisch Centrum | VU medisch centrum</span></b><span sty=
le=3D"font-size:
8.0pt;font-family:"Verdana","sans-serif";color:black">
</span><span style=3D"font-size:8.0pt;color:#10137D"><br>
</span><span style=3D"font-size:8.0pt;font-family:"Verdana","=
;sans-serif";
color:black">Afdeling KNO-Audiologie | EMGO Institute for Health and Care R=
esearch</span><span style=3D"color:black"><o:p></o:p></span></p>
<p class=3D"MsoNormal" style=3D"line-height:12.0pt;mso-line-height-rule:exa=
ctly"><span lang=3D"NL" style=3D"font-size:8.0pt;font-family:"Verdana&=
quot;,"sans-serif";color:black">Secretariaat Audiologie, Postbus =
7057, 1007 MB Amsterdam<br>
</span><b><span lang=3D"NL" style=3D"font-size:8.0pt;font-family:"Verd=
ana","sans-serif";
color:#E5053A">T</span></b><span lang=3D"NL" style=3D"font-size:8.0pt;font-=
family:
"Verdana","sans-serif";color:black"> (020) 444 09 69 |&=
nbsp;</span><b><span lang=3D"NL" style=3D"font-size:8.0pt;font-family:"=
;Verdana","sans-serif";color:#E5053A">F</span></b><span lang=
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(020) 444 09 83 | </span><b><span lang=3D"NL" style=3D"font-size:8.0p=
t;
font-family:"Verdana","sans-serif";color:#E5053A">E</sp=
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","sans-serif";color:black"> </span><span style=3D"colo=
r:#10137D"><a href="" href="mailto:c.smits@xxxxxxx">c.smits@xxxxxxx"><span lang=3D"NL" style=3D"fo=
nt-size:8.0pt;font-family:"Verdana","sans-serif"">c.smi=
ts@xxxxxxx</span></a></span><span lang=3D"NL" style=3D"font-size:8.0pt;font=
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</span><b><span lang=3D"NL" style=3D"font-size:8.0pt;font-family:"Verd=
ana","sans-serif";
color:#E5053A">W</span></b><span lang=3D"NL" style=3D"font-size:8.0pt;font-=
family:
"Verdana","sans-serif";color:black">
</span><span style=3D"color:#10137D"><a href="" href="http://www.AC-VUmc.nl" target="_blank">http://www.AC-VUmc.nl"><spa=
n lang=3D"NL" style=3D"font-size:8.0pt;font-family:
"Verdana","sans-serif"">www.AC-VUmc.nl</span></a></span=
><span lang=3D"NL" style=3D"font-size:8.0pt;font-family:"Verdana"=
,"sans-serif";color:black"> </span><span lang=3D"NL" style=
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color:#E5053A"> </span><span style=3D"font-size:8.0pt;font-family:&quo=
t;Verdana","sans-serif";color:purple"><a href="" href="http://www." target="_blank">http://www.=
CI-VUmc.nl"><span lang=3D"NL">www.CI-VUmc.nl</span></a></span><span lang=3D=
"NL" style=3D"color:#10137D"><o:p></o:p></span></p>
<p class=3D"MsoNormal" style=3D"line-height:12.0pt;mso-line-height-rule:exa=
ctly"><span lang=3D"NL" style=3D"color:#10137D"> <o:p></o:p></span></p=
>
<p class=3D"MsoNormal"><span lang=3D"NL" style=3D"color:#10137D"> <o:p=
></o:p></span></p>
<p class=3D"MsoNormal"><u><span lang=3D"NL" style=3D"font-size:9.0pt;color:=
gray">Disclaimer<o:p></o:p></span></u></p>
<p class=3D"MsoNormal"><span lang=3D"NL" style=3D"font-size:9.0pt;color:gra=
y">Deze e-mail is vertrouwelijk en alleen bestemd voor de geadresseerde. Al=
s deze e-mail niet voor u bestemd is, wordt u verzocht dit aan de afzender =
te melden, het bericht niet verder te
verspreiden en direct te vernietigen. VU medisch centrum staat niet in voo=
r de juiste en volledige overbrenging van de inhoud van deze e-mail.</span>=
<span lang=3D"NL"><o:p></o:p></span></p>
<p class=3D"MsoNormal"><span lang=3D"NL" style=3D"font-size:11.0pt;font-fam=
ily:"Calibri","sans-serif";
color:#1F497D"><o:p> </o:p></span></p>
<p class=3D"MsoNormal"><span lang=3D"NL" style=3D"font-size:11.0pt;font-fam=
ily:"Calibri","sans-serif";
color:#1F497D"><o:p> </o:p></span></p>
<p class=3D"MsoNormal"><span lang=3D"NL" style=3D"font-size:11.0pt;font-fam=
ily:"Calibri","sans-serif";
color:#1F497D"><o:p> </o:p></span></p>
<div>
<div style=3D"border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0cm =
0cm 0cm">
<p class=3D"MsoNormal"><b><span lang=3D"NL" style=3D"font-size:10.0pt;font-=
family:"Tahoma","sans-serif"">Van:</span></b><span lang=
=3D"NL" style=3D"font-size:10.0pt;font-family:"Tahoma","sans=
-serif""> AUDITORY - Research in Auditory Perception [mailto:AUDITORY@=
LISTS.MCGILL.CA]
<b>Namens </b>Pierre Divenyi<br>
<b>Verzonden:</b> Saturday, 25 January, 2014 17:33<br>
<b>Aan:</b> AUDITORY@xxxxxxxxxxxxxxx<br>
<b>Onderwerp:</b> Re: [AUDITORY] Reference for typical SNRs is public space=
s<o:p></o:p></span></p>
</div>
</div>
<p class=3D"MsoNormal"><o:p> </o:p></p>
<div>
<p class=3D"MsoNormal"><span style=3D"font-size:10.5pt;font-family:"Ca=
libri","sans-serif";
color:black">I agree with Bill except for one (crucial) assumption: in a co=
cktail-party situation the noise is not stationary (although, as Jont Allen=
once suggested, adding
talkers to the babble will make it approach stationarity). So, the 0.5 dB =
SNR is workable in a broad statistical sense and would have to be adjusted =
almost on a case-by-case basis.<o:p></o:p></span></p>
</div>
<div>
<p class=3D"MsoNormal"><span style=3D"font-size:10.5pt;font-family:"Ca=
libri","sans-serif";
color:black"><o:p> </o:p></span></p>
</div>
<div>
<p class=3D"MsoNormal"><span style=3D"font-size:10.5pt;font-family:"Ca=
libri","sans-serif";
color:black">-Pierre<o:p></o:p></span></p>
</div>
<div>
<p class=3D"MsoNormal"><span style=3D"font-size:10.5pt;font-family:"Ca=
libri","sans-serif";
color:black"><o:p> </o:p></span></p>
</div>
<div style=3D"border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0cm =
0cm 0cm">
<p class=3D"MsoNormal"><b><span style=3D"font-size:11.0pt;font-family:"=
;Calibri","sans-serif";
color:black">From:
</span></b><span style=3D"font-size:11.0pt;font-family:"Calibri",=
"sans-serif";
color:black">"Richard F. Lyon" <<a href="" href="mailto:dicklyon@ACM">dicklyon@ACM=
.ORG">dicklyon@xxxxxxx</a>><br>
<b>Reply-To: </b>"Richard F. Lyon" <<a href="" href="mailto:dicklyon">dicklyon=
@ACM.ORG">dicklyon@xxxxxxx</a>><br>
<b>Date: </b>Friday, January 24, 2014 at 10:16 PM<br>
<b>To: </b><<a href="" href="mailto:AUDITORY@xxxxxxxxxxxxxxx">AUDITORY@xxxxxxxxxxxxxxx">AUDITORY@LISTS.M=
CGILL.CA</a>><br>
<b>Subject: </b>Re: [AUDITORY] Reference for typical SNRs is public spaces<=
o:p></o:p></span></p>
</div>
<div>
<p class=3D"MsoNormal"><span style=3D"font-size:10.5pt;font-family:"Ca=
libri","sans-serif";
color:black"><o:p> </o:p></span></p>
</div>
<div>
<div>
<p class=3D"MsoNormal" style=3D"margin-bottom:12.0pt"><span style=3D"font-s=
ize:10.5pt;
font-family:"Calibri","sans-serif";color:black">I think=
Bill's point, which I agree with, is that the SNR is not determined by the=
noise in the space as much as it is by people
trying to communicate. The SNR that he estimates is not "in the=
space", but rather "at the ears of the listener" when the t=
alker is trying to communicate to that particular listener, above the noise=
. Other people trying to communicate to different listeners
make noise for this one. The SNR is therefore roughly constant, some=
where near 0 dB, almost anywhere that's not too quiet.<o:p></o:p></span></p=
>
</div>
<p class=3D"MsoNormal" style=3D"margin-bottom:12.0pt"><span style=3D"font-s=
ize:10.5pt;
font-family:"Calibri","sans-serif";color:black">For me,=
it's a little higher, after I make people speak up.<br>
<br>
Dick<o:p></o:p></span></p>
</div>
<div>
<p class=3D"MsoNormal" style=3D"margin-bottom:12.0pt"><span style=3D"font-s=
ize:10.5pt;
font-family:"Calibri","sans-serif";color:black"><o:p>&n=
bsp;</o:p></span></p>
<div>
<p class=3D"MsoNormal"><span style=3D"font-size:10.5pt;font-family:"Ca=
libri","sans-serif";
color:black">On Fri, Jan 24, 2014 at 1:51 PM, Bill Woods <<a href=""> lto:Bill_Woods@xxxxxxxxxxx" target=3D"_blank">Bill_Woods@xxxxxxxxxxx</a>>=
; wrote:<o:p></o:p></span></p>
<div>
<div>
<p class=3D"MsoNormal"><span style=3D"font-family:"Calibri","=
;sans-serif";color:black">Dear List,<o:p></o:p></span></p>
</div>
<div>
<p class=3D"MsoNormal"><span style=3D"color:black"> </span><span style=
=3D"font-family:"Calibri","sans-serif";color:black"><o:=
p></o:p></span></p>
</div>
<div>
<p class=3D"MsoNormal"><span style=3D"font-family:"Calibri","=
;sans-serif";color:black">Since we’re assuming Andy is asking ab=
out speech-to-noise ratio when referring to SNR in public spaces, I wondere=
d if the question couldn’t be answered by back-of-the-envelope
calculations using some assumptions and articulation index theory (AI).&nb=
sp; <o:p></o:p></span></p>
</div>
<div>
<p class=3D"MsoNormal"><span style=3D"font-family:"Calibri","=
;sans-serif";color:black"> <o:p></o:p></span></p>
</div>
<div>
<p class=3D"MsoNormal"><span style=3D"font-family:"Calibri","=
;sans-serif";color:black">It turned out there was quite a long list of=
assumptions behind the calculation (see below), but the resultant simple c=
alculation yielded a SNR of 0.5 dB, which is quite in line
with the values other posters have indicated may actually be present. Two =
other facts became apparent as I did this, however, and further motivate my=
posting.
<o:p></o:p></span></p>
</div>
<div>
<p class=3D"MsoNormal"><span style=3D"font-family:"Calibri","=
;sans-serif";color:black"> <o:p></o:p></span></p>
</div>
<div>
<p class=3D"MsoNormal"><span style=3D"font-family:"Calibri","=
;sans-serif";color:black">First, the long list of assumptions makes ap=
parent the long list of influences on the SNR in such a situation. These in=
fluences need to be characterized in any attempt to generalize
from SNR measurements in a given scenario, a fact other posters have allud=
ed to.<o:p></o:p></span></p>
</div>
<div>
<p class=3D"MsoNormal"><span style=3D"font-family:"Calibri","=
;sans-serif";color:black"> <o:p></o:p></span></p>
</div>
<div style=3D"margin-bottom:12.0pt">
<p class=3D"MsoNormal"><span style=3D"font-family:"Calibri","=
;sans-serif";color:black">Second, it is important to note that much wo=
rk has been done recently to model or empirically characterize these influe=
nces on speech intelligibility, and that, while the models
may require more computational power than found on the back of an envelope=
, they are no problem to execute on current laptop computers. The implicati=
on is that it should not be very difficult to determine a reasonably-accura=
te distribution of SNRs over wide
variation in the assumed listening scenario without any measurements. <o:p=
></o:p></span></p>
</div>
<div>
<p class=3D"MsoNormal"><span style=3D"font-family:"Calibri","=
;sans-serif";color:black">Cheers,<o:p></o:p></span></p>
</div>
<div>
<p class=3D"MsoNormal"><span style=3D"font-family:"Calibri","=
;sans-serif";color:black">Bill<o:p></o:p></span></p>
</div>
<div>
<p class=3D"MsoNormal"><span style=3D"color:black"> </span><span style=
=3D"font-family:"Calibri","sans-serif";color:black"><o:=
p></o:p></span></p>
</div>
<table class=3D"MsoNormalTable" border=3D"0" cellpadding=3D"0" width=3D"377=
" style=3D"width:282.75pt;
margin-left:5.4pt">
<tbody>
<tr>
<td style=3D"padding:.75pt .75pt .75pt .75pt">
<p class=3D"MsoNormal"><span style=3D"font-family:"Arial","s=
ans-serif";color:#17365D">Bill Woods, PhD<br>
</span><span style=3D"font-size:10.0pt;font-family:"Arial","=
sans-serif";
color:#595959">Principal Research Scientist | Starkey Hearing R=
esearch Center<br>
2150 Shattuck Ave. | Suite 408 | Berkeley, CA =
;94704-1345<br>
T: <a href="" target=3D"_blank">510-8=
45-4876 x 14</a>
</span><o:p></o:p></p>
</td>
</tr>
<tr>
<td style=3D"padding:.75pt .75pt .75pt .75pt">
<p class=3D"MsoNormal"><a href="" href="http://www.starkey.com/" target="_blank">http://www.starkey.com/" target=3D"_blank=
"><span style=3D"font-size:10.0pt;font-family:"Arial","sans-=
serif"">starkey.com</span></a><span style=3D"font-size:10.0pt;font-fam=
ily:"Arial","sans-serif";color:#0000F6"> </span><s=
pan style=3D"font-size:10.0pt;font-family:"Arial","sans-seri=
f";color:#595959">|</span><span style=3D"font-size:10.0pt;font-family:=
"Arial","sans-serif";color:#0000F6"> </span><a hre=
f=3D"http://www.starkeyresearch.com" target=3D"_blank"><span style=3D"font-=
size:
10.0pt;font-family:"Arial","sans-serif"">starkeyresea=
rch.com</span></a><span style=3D"font-size:10.0pt;font-family:"Arial&q=
uot;,"sans-serif";color:#0000F6"> </span><span style=3D"font=
-size:10.0pt;font-family:"Arial","sans-serif";color:#59=
5959">|</span><span style=3D"font-size:10.0pt;font-family:"Arial"=
,"sans-serif";color:#0000F6"> </span><a href="" href="http://maps." target="_blank">http://maps.=
google.com/maps?q=3D2150+Shattuck+Avenue,+Berkeley,+CA+=
94704&hl=3Den&ll=3D37.869941,-122.268219&spn=3D0.028152,0.03806=
6&sll=3D37.86923,-122.273197&sspn=3D0.056305,0.076132&z=3D15" t=
arget=3D"_blank"><span style=3D"font-size:10.0pt;font-family:"Arial&qu=
ot;,"sans-serif"">map</span></a><span style=3D"font-size:10.0pt;f=
ont-family:"Arial","sans-serif";color:#0000F6"> </=
span><span style=3D"font-size:10.0pt;font-family:"Arial","sa=
ns-serif";color:#595959">|</span><span style=3D"font-size:10.0pt;font-=
family:"Arial","sans-serif";color:#0000F6"> </span=
><a href="" href="mailto:william_woods@xxxxxxxxxxx">william_woods@xxxxxxxxxxx" target=3D"_blank"><span style=
=3D"font-size:10.0pt;font-family:"Arial","sans-serif"">=
email</span></a><o:p></o:p></p>
</td>
</tr>
<tr>
<td style=3D"padding:.75pt .75pt .75pt .75pt"></td>
</tr>
<tr>
<td style=3D"padding:.75pt .75pt .75pt .75pt"></td>
</tr>
</tbody>
</table>
<div>
<p class=3D"MsoNormal"><span style=3D"color:black"> </span><span style=
=3D"font-family:"Calibri","sans-serif";color:black"><o:=
p></o:p></span></p>
</div>
<div>
<p class=3D"MsoNormal"><span style=3D"font-family:"Calibri","=
;sans-serif";color:black">The assumptions are:<o:p></o:p></span></p>
</div>
<p class=3D"MsoNormal" style=3D"mso-margin-top-alt:auto;mso-margin-bottom-a=
lt:auto;
margin-left:0cm;text-indent:-18.0pt;mso-list:l0 level1 lfo1">
<![if !supportLists]><span style=3D"font-family:"Calibri","s=
ans-serif";color:black"><span style=3D"mso-list:
Ignore">1.<span style=3D"font:7.0pt "Times New Roman""> &nbs=
p;
</span></span></span><![endif]><span style=3D"font-family:"Calibri&quo=
t;,"sans-serif";
color:black">Talkers have no hearing loss and no cognitive loss.<o:p></o:p>=
</span></p>
<p class=3D"MsoNormal" style=3D"mso-margin-top-alt:auto;mso-margin-bottom-a=
lt:auto;
margin-left:0cm;text-indent:-18.0pt;mso-list:l0 level1 lfo1">
<![if !supportLists]><span style=3D"font-family:"Calibri","s=
ans-serif";color:black"><span style=3D"mso-list:
Ignore">2.<span style=3D"font:7.0pt "Times New Roman""> &nbs=
p;
</span></span></span><![endif]><span style=3D"font-family:"Calibri&quo=
t;,"sans-serif";
color:black">The talkers are facing each other and speaking in their “=
;mother tongue”.<o:p></o:p></span></p>
<p class=3D"MsoNormal" style=3D"mso-margin-top-alt:auto;mso-margin-bottom-a=
lt:auto;
margin-left:0cm;text-indent:-18.0pt;mso-list:l0 level1 lfo1">
<![if !supportLists]><span style=3D"font-family:"Calibri","s=
ans-serif";color:black"><span style=3D"mso-list:
Ignore">3.<span style=3D"font:7.0pt "Times New Roman""> &nbs=
p;
</span></span></span><![endif]><span style=3D"font-family:"Calibri&quo=
t;,"sans-serif";
color:black">We know the percent-correct (%C) targeted by the talkers and i=
t is less than 100% (it’s a challenging environment).<o:p></o:p></spa=
n></p>
<p class=3D"MsoNormal" style=3D"mso-margin-top-alt:auto;mso-margin-bottom-a=
lt:auto;
margin-left:0cm;text-indent:-18.0pt;mso-list:l0 level1 lfo1">
<![if !supportLists]><span style=3D"font-family:"Calibri","s=
ans-serif";color:black"><span style=3D"mso-list:
Ignore">4.<span style=3D"font:7.0pt "Times New Roman""> &nbs=
p;
</span></span></span><![endif]><span style=3D"font-family:"Calibri&quo=
t;,"sans-serif";
color:black">We know the nature of the speech in such a conversation, from =
a low-context vs. high-context perspective.<o:p></o:p></span></p>
<p class=3D"MsoNormal" style=3D"mso-margin-top-alt:auto;mso-margin-bottom-a=
lt:auto;
margin-left:0cm;text-indent:-18.0pt;mso-list:l0 level1 lfo1">
<![if !supportLists]><span style=3D"font-family:"Calibri","s=
ans-serif";color:black"><span style=3D"mso-list:
Ignore">5.<span style=3D"font:7.0pt "Times New Roman""> &nbs=
p;
</span></span></span><![endif]><span style=3D"font-family:"Calibri&quo=
t;,"sans-serif";
color:black">The talkers are within their critical distance (i.e., ignore r=
everberation of talkers’ speech).<o:p></o:p></span></p>
<p class=3D"MsoNormal" style=3D"mso-margin-top-alt:auto;mso-margin-bottom-a=
lt:auto;
margin-left:0cm;text-indent:-18.0pt;mso-list:l0 level1 lfo1">
<![if !supportLists]><span style=3D"font-family:"Calibri","s=
ans-serif";color:black"><span style=3D"mso-list:
Ignore">6.<span style=3D"font:7.0pt "Times New Roman""> &nbs=
p;
</span></span></span><![endif]><span style=3D"font-family:"Calibri&quo=
t;,"sans-serif";
color:black">We know the long-term spectral shape of speech at the eardrums=
.<o:p></o:p></span></p>
<p class=3D"MsoNormal" style=3D"mso-margin-top-alt:auto;mso-margin-bottom-a=
lt:auto;
margin-left:0cm;text-indent:-18.0pt;mso-list:l0 level1 lfo1">
<![if !supportLists]><span style=3D"font-family:"Calibri","s=
ans-serif";color:black"><span style=3D"mso-list:
Ignore">7.<span style=3D"font:7.0pt "Times New Roman""> &nbs=
p;
</span></span></span><![endif]><span style=3D"font-family:"Calibri&quo=
t;,"sans-serif";
color:black">We know the long-term spectral shape of noise at the eardrums.=
<o:p></o:p></span></p>
<p class=3D"MsoNormal" style=3D"mso-margin-top-alt:auto;mso-margin-bottom-a=
lt:auto;
margin-left:0cm;text-indent:-18.0pt;mso-list:l0 level1 lfo1">
<![if !supportLists]><span style=3D"font-family:"Calibri","s=
ans-serif";color:black"><span style=3D"mso-list:
Ignore">8.<span style=3D"font:7.0pt "Times New Roman""> &nbs=
p;
</span></span></span><![endif]><span style=3D"font-family:"Calibri&quo=
t;,"sans-serif";
color:black">The noise is stationary.<o:p></o:p></span></p>
<p class=3D"MsoNormal" style=3D"mso-margin-top-alt:auto;mso-margin-bottom-a=
lt:auto;
margin-left:0cm;text-indent:-18.0pt;mso-list:l0 level1 lfo1">
<![if !supportLists]><span style=3D"font-family:"Calibri","s=
ans-serif";color:black"><span style=3D"mso-list:
Ignore">9.<span style=3D"font:7.0pt "Times New Roman""> &nbs=
p;
</span></span></span><![endif]><span style=3D"font-family:"Calibri&quo=
t;,"sans-serif";
color:black">The noise is diffuse.<o:p></o:p></span></p>
<p class=3D"MsoNormal" style=3D"mso-margin-top-alt:auto;mso-margin-bottom-a=
lt:auto;
margin-left:0cm;text-indent:-18.0pt;mso-list:l0 level1 lfo1">
<![if !supportLists]><span style=3D"font-family:"Calibri","s=
ans-serif";color:black"><span style=3D"mso-list:
Ignore">10.<span style=3D"font:7.0pt "Times New Roman"">
</span></span></span><![endif]><span style=3D"font-family:"Calibri&quo=
t;,"sans-serif";color:black">The diffuse noise in combination wit=
h diotic direct-wave target speech generates the equivalent of an “in=
ternal” wideband binaural SNR improvement of ~1.0 dB over monaural
listening.<o:p></o:p></span></p>
<p class=3D"MsoNormal" style=3D"mso-margin-top-alt:auto;mso-margin-bottom-a=
lt:auto;
margin-left:0cm;text-indent:-18.0pt;mso-list:l0 level1 lfo1">
<![if !supportLists]><span style=3D"font-family:"Calibri","s=
ans-serif";color:black"><span style=3D"mso-list:
Ignore">11.<span style=3D"font:7.0pt "Times New Roman"">
</span></span></span><![endif]><span style=3D"font-family:"Calibri&quo=
t;,"sans-serif";color:black">Overall level is not too high (i.e.,=
no “roll-over” effect for intelligibility has occurred).<o:p><=
/o:p></span></p>
<p class=3D"MsoNormal" style=3D"mso-margin-top-alt:auto;mso-margin-bottom-a=
lt:auto;
margin-left:0cm;text-indent:-18.0pt;mso-list:l0 level1 lfo1">
<![if !supportLists]><span style=3D"font-family:"Calibri","s=
ans-serif";color:black"><span style=3D"mso-list:
Ignore">12.<span style=3D"font:7.0pt "Times New Roman"">
</span></span></span><![endif]><span style=3D"font-family:"Calibri&quo=
t;,"sans-serif";color:black">We’re not including lip readin=
g.<o:p></o:p></span></p>
<div>
<p class=3D"MsoNormal"><span style=3D"color:black"> </span><span style=
=3D"font-family:"Calibri","sans-serif";color:black"><o:=
p></o:p></span></p>
</div>
<div>
<p class=3D"MsoNormal"><span style=3D"font-family:"Calibri","=
;sans-serif";color:black">These assumptions allow one to, first, deter=
mine the AI needed to achieve the assumed target %C given the assumed type =
of speech, and, second, determine the SNR required with
the assumed spectral shapes to obtain that AI.<o:p></o:p></span></p>
</div>
<div>
<p class=3D"MsoNormal"><span style=3D"font-family:"Calibri","=
;sans-serif";color:black"> <o:p></o:p></span></p>
</div>
<div>
<p class=3D"MsoNormal"><span style=3D"font-family:"Calibri","=
;sans-serif";color:black">For instance, assuming talkers want 95%C wit=
h “unfamiliar sentences” then using the polynomial fits from Sh=
erbecoe and Studebaker (JASA 1990) of the ANSI S3.5-1969 transfer functions
between AI and %C, our talkers would need an AI of 0.45. If we assume the =
noise and speech have the same long-term spectral shape then the SNR can be=
determined from (SNR+12)/30=3D0.45 (staying with the 1969 AI method), =
yielding SNR =3D 1.5 dB. Subtracting the
binaural SNR improvement yields 0.5 dB. <o:p></o:p></span></p>
</div>
<div>
<p class=3D"MsoNormal"><span style=3D"color:black"> </span><span style=
=3D"font-family:"Calibri","sans-serif";color:black"><o:=
p></o:p></span></p>
</div>
<div>
<div>
<p class=3D"MsoNormal"><b><span style=3D"font-size:10.0pt;font-family:"=
;Tahoma","sans-serif";
color:black">From:</span></b><span style=3D"font-size:10.0pt;font-family:&q=
uot;Tahoma","sans-serif";
color:black"> AUDITORY - Research in Auditory Perception [<a href=""> :AUDITORY@xxxxxxxxxxxxxxx" target=3D"_blank">mailto:AUDITORY@LISTS.MCGILL.C=
A</a>]
<b>On Behalf Of </b>Andy Sabin<o:p></o:p></span></p>
</div>
<p class=3D"MsoNormal"><b><span style=3D"font-size:10.0pt;font-family:"=
;Tahoma","sans-serif";
color:black">Sent:</span></b><span style=3D"font-size:10.0pt;font-family:&q=
uot;Tahoma","sans-serif";
color:black"> Wednesday, January 22, 2014 9:53 AM<o:p></o:p></span></p>
<div>
<p class=3D"MsoNormal"><span style=3D"font-size:10.0pt;font-family:"Ta=
homa","sans-serif";
color:black"><br>
<b>To:</b> <a href="" href="mailto:AUDITORY@xxxxxxxxxxxxxxx">AUDITORY@xxxxxxxxxxxxxxx" target=3D"_blank">AU=
DITORY@xxxxxxxxxxxxxxx</a><br>
<b>Subject:</b> Reference for typical SNRs is public spaces<o:p></o:p></spa=
n></p>
</div>
</div>
<div>
<div>
<p class=3D"MsoNormal"><span style=3D"color:black"> </span><span style=
=3D"font-family:"Calibri","sans-serif";color:black"><o:=
p></o:p></span></p>
</div>
<div>
<p class=3D"MsoNormal"><span style=3D"color:black">Hi List, </span><sp=
an style=3D"font-family:"Calibri","sans-serif";color:bl=
ack"><o:p></o:p></span></p>
</div>
<div>
<p class=3D"MsoNormal"><span style=3D"color:black"> </span><span style=
=3D"font-family:"Calibri","sans-serif";color:black"><o:=
p></o:p></span></p>
</div>
<div>
<p class=3D"MsoNormal"><span style=3D"color:black">Can anyone point me to a=
reference showing SNRs that are typically observed in public spaces (e.g.,=
restaurants, bars ...etc)? I can find this info for overall SPL, but am ha=
ving a hard time finding it for SNR. </span><span style=3D"font-family=
:"Calibri","sans-serif";
color:black"><o:p></o:p></span></p>
</div>
<div>
<p class=3D"MsoNormal"><span style=3D"color:black"> </span><span style=
=3D"font-family:"Calibri","sans-serif";color:black"><o:=
p></o:p></span></p>
</div>
<div>
<p class=3D"MsoNormal"><span style=3D"color:black">Thanks</span><span style=
=3D"font-family:"Calibri","sans-serif";color:black"><o:=
p></o:p></span></p>
</div>
<div>
<p class=3D"MsoNormal"><span style=3D"color:black">Andy Sabin</span><span s=
tyle=3D"font-family:"Calibri","sans-serif";color:black"=
><o:p></o:p></span></p>
</div>
<div>
<p class=3D"MsoNormal"><span style=3D"color:black"> </span><span style=
=3D"font-family:"Calibri","sans-serif";color:black"><o:=
p></o:p></span></p>
</div>
</div>
</div>
</div>
<p class=3D"MsoNormal"><span style=3D"font-size:10.5pt;font-family:"Ca=
libri","sans-serif";
color:black"><o:p> </o:p></span></p>
</div>
</div>
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