Re: AUDITORY Digest - 30 Aug 2006 to 31 Aug 2006 (#2006-197)

On 8/31/06, AUDITORY automatic digest system <LISTSERV@xxxxxxxxxxxxxxx> wrote:

There are 7 messages totalling 424 lines in this issue.

Topics of the day:

1. Cochlear liquid-particle trajectories.
2. tympanometry probe tone level? (4)
3. STFT vs Power Spectral in Musical recognition system ? (2)

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Date:    Thu, 31 Aug 2006 10:37:03 +0000
From:    "reinifrosch@xxxxxxxxxx" <reinifrosch@xxxxxxxxxx>
Subject: Cochlear liquid-particle trajectories.

Dear List,

The calculations on the "new" basilar-membrane stiffness
formula take longer than expected. If they give interesting
results, I shall communicate them in a week or two.

Yesterday I received a cochlear-mechanics report on a
transmission-line model, containing a graph of liquid
streamlines which disagree with what I have learned.

In the case of small-displacement surface waves on
the ocean it is helpful to change to a coordinate system
which moves along with the wave crests:

x' = x - c * t

(where x = longitudinal coordinate, t = time, c = phase
velocity). In the primed coordinate system, the liquid
particles make a stationary flow in the -x'-direction.
At the crests, the streamlines are far apart from each other,
so that the velocity v_x' of the particles is comparatively low.

Transformation back to the lab system yields closed,
elliptical liquid-particle trajectories (circular for short
waves).
In long waves (e.g., tsunamis far from the coast)  the particle
trajectories are oblong ellipses; at the ocean floor, the length
of the short ellipse axis is zero.

In cochlear waves, the phase velocity c decreases if x
increases; the liquid-particle trajectories, however, are
similar (I believe) to those in ocean waves, i.e., closed
and approximately elliptical.

The elliptical particle trajectories do not cross the basilar
membrane (BM). At the BM, the liquid particles move
along the BM. That is why the mass of the organ-of-Corti
cells (which in the idealistic models do not move along
the BM) plays a role even if their density is equal to
that of the liquid.

A good introduction into cochlear waves was written
by the late G.K. Yates: Chapter 2 of the book "Hearing",
B.C.J. Moore, ed., Academic Press, San Diego,
1995, Section II.B , pages 49-53.

With best wishes,

Reinhart Frosch.

Reinhart Frosch,
Dr. phil. nat.,
r. PSI and ETH Zurich,
Sommerhaldenstr. 5B,
CH-5200 Brugg.
Phone: 0041 56 441 77 72.
Mobile: 0041 79 754 30 32.
E-mail: reinifrosch@xxxxxxxxxx .

------------------------------

Date:    Thu, 31 Aug 2006 10:08:03 -0500
From:    "Ferguson, Sarah Hargus" < safergus@xxxxxx>
Subject: tympanometry probe tone level?

Hello list! Students ask the darnedest questions. Today in Intro to
Audiology, one of the students asked what the presentation level is for
the probe tone used in tympanometry. I didn't find it in a quick Google
search (not even a manufacturers' specs I looked at) or during a quick
peek in a classic audiology textbook - perhaps someone out there knows
off-hand what it is?=20

~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~=20
Sarah Hargus Ferguson, Ph.D., CCC-A
Assistant Professor
Department of Speech-Language-Hearing: Sciences and Disorders=20
University of Kansas=20
Dole Center=20
1000 Sunnyside Ave., Room 3001=20
Lawrence, KS  66045
office: (785)864-1116
Speech Acoustics and Perception Lab: (785)864-0610=20
http://www.ku.edu/~splh/ipcd/Faculty/FergusonBio.html

------------------------------

Date:    Thu, 31 Aug 2006 11:45:04 EDT
From:    Harriet B Jacobster <Hjacobster@xxxxxxx>
Subject: Re: tympanometry probe tone level?

-------------------------------1157039103
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It's around 85 dBSPL

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Harriet Jacobster, Au.D., CCC-A, FAAA
Board Certified in Audiology

-------------------------------1157039103
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<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<HTML><HEAD>
<META http-equiv=3DContent-Type content=3D"text/html; charset=3DUS-ASCII">
<META content=3D"MSHTML 6.00.2900.2963" name=3DGENERATOR></HEAD>
<BODY id=3Drole_body style=3D"FONT-SIZE: 10pt; COLOR: #000000; FONT-FAMILY:=20=
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bottomMargin=3D7 leftMargin=3D7 topMargin=3D7 rightMargin=3D7><FONT id=3Drol=
e_document=20
face=3DArial color=3D#000000 size=3D2>
<DIV>It's around 85 dBSPL</DIV>
<DIV> </DIV>
<DIV>~~~~~~~~~~~~~~~~~~~~~~~~~~~~~</DIV>
<DIV>Harriet Jacobster, Au.D., CCC-A, FAAA</DIV>
<DIV>Board Certified in Audiology</DIV></FONT></BODY></HTML>

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Date:    Thu, 31 Aug 2006 08:47:42 -0700
From:    Navid Shahnaz <nshahnaz@xxxxxxxxxxxxxxxxxx >
Subject: Re: tympanometry probe tone level?

Hi
It depends on the probe tone frequency and it is usually set at a level bel=
ow the level the elicit the aural reflex. It varies a bit between manufactu=
rer; however, it is close the the following values.
226 Hz @ 85dB SPL =B1 1.5dB
1000 Hz (a probe tone frequency of choice for infant assessment) @ 75dB SP=
L =B1 1.5dB
Hope this helps.
Best
Navid
-------------------------------
Navid Shahnaz, Ph.D
Assistant Professor
School of Audiology & Speech Sciences
Faculty of Medicine
5804 Fairview Ave.
Vancouver, B.C. V6t 1Z3
Canada
Tel. 604-822-5953
Fax. 604-822-6569
E-mail: nshahnaz@xxxxxxxxxxxxxxxxxx
Website: http://www.audiospeech.ubc.ca/school/faculty/navid/

---------- Original Message ----------------------------------
From: "Ferguson, Sarah Hargus" <safergus@xxxxxx>
Reply-To: "Ferguson, Sarah Hargus" < safergus@xxxxxx>
Date:          Thu, 31 Aug 2006 10:08:03 -0500

>Hello list! Students ask the darnedest questions. Today in Intro to
>Audiology, one of the students asked what the presentation level is for
>the probe tone used in tympanometry. I didn't find it in a quick Google
>search (not even a manufacturers' specs I looked at) or during a quick
>peek in a classic audiology textbook - perhaps someone out there knows
>off-hand what it is?
>
>~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
>Sarah Hargus Ferguson, Ph.D., CCC-A
>Assistant Professor
>Department of Speech-Language-Hearing: Sciences and Disorders
>University of Kansas
>Dole Center
>1000 Sunnyside Ave., Room 3001
>Lawrence, KS  66045
>office: (785)864-1116
>Speech Acoustics and Perception Lab: (785)864-0610
> http://www.ku.edu/~splh/ipcd/Faculty/FergusonBio.html
>

________________________________________________________________
Sent via the WebMail system at audiospeech.ubc.ca

------------------------------

Date:    Thu, 31 Aug 2006 11:20:43 -0500
From:    Jeremy Federman <jeremy.federman@xxxxxxxxxxxxxx >
Subject: Re: tympanometry probe tone level?

Hi -

I suspect it depends on the frequency being used (and maybe the equipment,
too), but I believe the probe tone level at the standard 226 Hz should be 85
dB SPL plus or minus 1.5 dB.  For additional calibration info, you could
check the ANSI standard...

With kind regards,

Jeremy

On 8/31/06 10:08 AM, "Ferguson, Sarah Hargus" < safergus@xxxxxx> wrote:

> Hello list! Students ask the darnedest questions. Today in Intro to
> Audiology, one of the students asked what the presentation level is for
> the probe tone used in tympanometry. I didn't find it in a quick Google
> search (not even a manufacturers' specs I looked at) or during a quick
> peek in a classic audiology textbook - perhaps someone out there knows
> off-hand what it is?
>
> ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
> Sarah Hargus Ferguson, Ph.D., CCC-A
> Assistant Professor
> Department of Speech-Language-Hearing: Sciences and Disorders
> University of Kansas
> Dole Center
> 1000 Sunnyside Ave., Room 3001
> Lawrence, KS  66045
> office: (785)864-1116
> Speech Acoustics and Perception Lab: (785)864-0610
> http://www.ku.edu/~splh/ipcd/Faculty/FergusonBio.html
>

--
Jeremy Federman, MS, CCC-A
Vanderbilt University Medical Center
Dan Maddox Hearing Aid Research Lab
Department of Hearing and Speech Sciences
Medical Center East, South Tower
1215 21st Ave. South, Room 8310
Nashville, TN  37232-8242
jeremy.federman@xxxxxxxxxxxxxx

------------------------------

Date:    Thu, 31 Aug 2006 18:32:56 -0400
From:    Arturo Camacho < acamacho@xxxxxxxxxxxx>
Subject: Re: STFT vs Power Spectral in Musical recognition system ?

One problem of the square-root compression is that its slope
approaches infinity as the magnitude M approaches zero. A more
appropriate approach may be to use log(1+KM), where K is a constant to
be determined. The response of this function is almost logarithmic for
high magnitudes and almost linear for low magnitudes. Of course, the
determination of the optimal value for K given an input is not
trivial.

Arturo
--
__________________________________________________

Arturo Camacho
PhD Candidate
Computer and Information Science and Engineering
University of Florida

E-mail: acamacho@xxxxxxxxxxxx
Web page: www.cise.ufl.edu/~acamacho
__________________________________________________

On Fri, 25 Aug 2006, Richard F. Lyon wrote:

> Edwin,
>
> A power spectral density is only defined for stationary signals, not
> music.  The STFT generalizes it to short segments, if you use the
> squared magnitude.
>
> The difference between the absolute value, square, log, etc. are just
> point nonlinearities that do not change the information content, but
> do change the metric structure of the space a bit.  Log is too
> compressed, leading to too much emphasis on near-silent segments,
> while the square (the power you ask about) is too expanded, leading
> to too much emphasis on the louder parts.  A good compromise is
> around a square root or cube root of magnitude (roughly matching
> perceptual magnitude via Stevens's law), but the magnitude itself is
> also sometimes acceptable, depending on what you're doing.
>
> Dick
>
> At 7:12 AM -0700 8/25/06, Edwin Sianturi wrote:
> >Content-Type: text/html
> >X-MIME-Autoconverted: from 8bit to quoted-printable by
> > torrent.cc.mcgill.ca id k7PED6jh031610
> >
> >Hello,
> >
> >I am just a master student, doing my internship. Right now, I am
> >building a musical instrument recognition system. I have read
> >several papers on it, and I am just curious:
> >
> >All the papers/journals that I have read use the STFT, a.k.a the
> >|X(t,f)| of a signal x(t), in order to extract several (spectral)
> >features to be used as the input to the recognition system.
> >
> >What are the reasons behind using the |X(t,f)| instead of using the
> >"power spectral" |X(t,f)|^2 ?
> >(technically speaking, a power spectral density is the expectation
> >of |X(f)|^2, i.e. E(|X(f)|^2) )
> >
> >Thanks in advance,
> >
> >Edwin SIANTURI
> >
>
>

------------------------------

Date:    Thu, 31 Aug 2006 16:00:31 -0700
From:    "Richard F. Lyon" <DickLyon@xxxxxxx>
Subject: Re: STFT vs Power Spectral in Musical recognition system ?

Arturo, I totally agree with the idea of using log(1 + KM), or log(M
+ epsilon) as I usually do it.  This kind of nonlinearity is
especially important in systems with an imprecisely known zero level
or a variable noise floor.  On the other hand, a power law, though it
has an infinite slope at 0, is not half as bad as a plain log, and
lots of people use that anyway.  A stabilized power law, like (M +
epsilon)^(1/3) is another good choice, probably more in line with
perception that letting it go log-like at high magnitudes.  With any
of these, adjusting your parameters to accommodate a realistic range
of input signal levels becomes important; you can no longer ignore
scale factors and hope for algorithms to work fine on inputs varying
over many orders of magnitude in scale.

Dick

At 6:32 PM -0400 8/31/06, Arturo Camacho wrote:
>One problem of the square-root compression is that its slope
>approaches infinity as the magnitude M approaches zero. A more
>appropriate approach may be to use log(1+KM), where K is a constant to
>be determined. The response of this function is almost logarithmic for
>high magnitudes and almost linear for low magnitudes. Of course, the
>determination of the optimal value for K given an input is not
>trivial.
>
>Arturo
>--
>__________________________________________________
>
>  Arturo Camacho
>  PhD Candidate
>  Computer and Information Science and Engineering
>  University of Florida
>
>  E-mail: acamacho@xxxxxxxxxxxx
>  Web page: www.cise.ufl.edu/~acamacho
>__________________________________________________
>
>On Fri, 25 Aug 2006, Richard F. Lyon wrote:
>
>>  Edwin,
>>
>>  A power spectral density is only defined for stationary signals, not
>>  music.  The STFT generalizes it to short segments, if you use the
>>  squared magnitude.
>>
>>  The difference between the absolute value, square, log, etc. are just
>>  point nonlinearities that do not change the information content, but
>>  do change the metric structure of the space a bit.  Log is too
>>  compressed, leading to too much emphasis on near-silent segments,
>>  while the square (the power you ask about) is too expanded, leading
>>  to too much emphasis on the louder parts.  A good compromise is
>>  around a square root or cube root of magnitude (roughly matching
>>  perceptual magnitude via Stevens's law), but the magnitude itself is
>>  also sometimes acceptable, depending on what you're doing.
>>
>>  Dick
>>
>>  At 7:12 AM -0700 8/25/06, Edwin Sianturi wrote:
>>  >Content-Type: text/html
>>  >X-MIME-Autoconverted: from 8bit to quoted-printable by
>>  > torrent.cc.mcgill.ca id k7PED6jh031610
>>  >
>>  >Hello,
>>  >
>>  >I am just a master student, doing my internship. Right now, I am
>>  >building a musical instrument recognition system. I have read
>>  >several papers on it, and I am just curious:
>>  >
>>  >All the papers/journals that I have read use the STFT, a.k.a the
>>  >|X(t,f)| of a signal x(t), in order to extract several (spectral)
>>  >features to be used as the input to the recognition system.
>>  >
>>  >What are the reasons behind using the |X(t,f)| instead of using the
>>  >"power spectral" |X(t,f)|^2 ?
>>  >(technically speaking, a power spectral density is the expectation
>>  >of |X(f)|^2, i.e. E(|X(f)|^2) )
>>  >
>>  >Thanks in advance,
>>  >
>>  >Edwin SIANTURI
>>  >
>>
>>

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End of AUDITORY Digest - 30 Aug 2006 to 31 Aug 2006 (#2006-197)
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