Re: AUDITORY Digest - 14 Oct 2011 to 17 Oct 2011

Subject: Audio Glitch in Matlab

The truncation of the auditory signals less than 500 ms was also seen in windows 7 and MATLAB version 10. I have even noticed this kind of problems in Adobe Audition software. I have not used ASIO sound card. I am not sure about other sound playing softwares.

Vijaya Kumar Narne PhD

Lecturer in Audiology

AIISH

Mysore

Date: Mon, 17 Oct 2011 09:57:17 -0400
From: Patrick Zurek <pat@xxxxxxxx>
Subject: Audio Glitch in Matlab

This is a multi-part message in MIME format.
--------------030103020706040808060701
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Content-Transfer-Encoding: 7bit

I'm writing to notify list readers of a problem playing audio using Matlab.

The problem is that brief signals are truncated, and it happens using
any of the common commands for playing audio (wavplay, sound, and the
play method of the audioplayer object).

I can't specify the exact conditions under which the truncation occurs.
However, with a sample rate of 44.1 kHz, signals shorter than about 500
msec are truncated. I haven't looked much at other sample rates.

A simple work-around for the problem is to pad the end of the signal
with a sufficient number of zeros that truncation occurs during the zero
segment. I've found that at least 2000 zeros need to be added to assure
no truncation of a 10-msec signal (with a sample rate of 44.1kHz).

I've brought this problem to the attention of The Mathworks. They
confirmed the problem, which they attribute to a bug in their driver.

The Mathworks also informed me that the problem has been solved in their
latest release (R2011b) for playing using audioplayer, but not
necessarily for the other audio commands. I've confirmed this in very
limited tests.

The following is a piece of code that you can use to observe the
truncation. It creates a 100-msec, 1-kHz sine wave, applies a hanning
window, and then plays it first with zero-padding and then without. You
should be able to hear the click at the end of the second tone, which is
not present on the first. If not, you can see it on an oscilloscope.

%%%%%%%%%%%%%%%%%%%%
fs = 44100;
f = 1000;
T = 0.1;
nPad = 2000;

nS = round(fs*T);

y = sin(2.*pi*f/fs*(1:nS)');
w = .5*(1 - cos(2*pi*(1:nS)'/(nS+1)));
y = w.*y;
yPad = [y; zeros(nPad,1)];

wavplay(yPad, fs, 'sync')
pause(0.5)
wavplay(y, fs, 'sync')
%%%%%%%%%%%%%%%%%%%%%

--
Patrick M. Zurek
President

Sensimetrics Corporation
14 Summer St.
Suite 403
Malden, MA 02148
Tel: 781-399-0858 x237
Fax: 781-399-0853
email: pat@xxxxxxxx
web: www.sens.com

On Mon, Oct 17, 2011 at 10:02 PM, AUDITORY automatic digest system <LISTSERV@xxxxxxxxxxxxxxx> wrote:

There are 6 messages totalling 1517 lines in this issue.

Topics in this special issue:

1. CFP: Special Issue on Speech Separation and Recognition in Multisource
Environments
2. Audio Glitch in Matlab (5)

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

Date: Mon, 17 Oct 2011 12:29:02 +0100
From: jon <j.barker@xxxxxxxxxxxxxx>
Subject: CFP: Special Issue on Speech Separation and Recognition in Multisource Environments

--Apple-Mail=_EDC2B160-FC49-4860-979B-9662B080E0E5
Content-Transfer-Encoding: quoted-printable
Content-Type: text/plain;
charset=windows-1252

[Apologies for multiple postings]

+++++++++++++++++++++++++++++++++++++++++++

COMPUTER SPEECH AND LANGUAGE
http://www.elsevier.com/locate/csl

Special issue on
SPEECH SEPARATION AND RECOGNITION IN MULTISOURCE ENVIRONMENTS

Submission Deadline: NOVEMBER 30, 2011

+++++++++++++++++++++++++++++++++++++++++++

One of the chief difficulties of building distant-microphone speech =
recognition systems for use in everyday applications is that the noise =
background is typically `multisource'. A speech recognition system =
designed to operate in a family home, for example, must contend with =
competing noise from televisions and radios, children playing, vacuum =
cleaners, and outdoors noises from open windows. Despite their =
complexity, such environments contain structure that can be learnt and =
exploited using advanced source separation, machine learning and speech =
recognition techniques such as those presented at the 1st International =
Workshop on Machine Listening in Multisource Environments (CHiME 2011). =
http://spandh.dcs.shef.ac.uk/projects/chime/workshop/

This special issue solicits papers describing advances in speech =
separation and recognition in multisource noise environments, including =
theoretical developments, algorithms or systems.

Examples of topics relevant to the special issue include:
=95 multiple speaker localization, beamforming and source separation,
=95 hearing inspired approaches to multisource processing,
=95 background noise tracking and modelling,
=95 noise-robust speech decoding,
=95 model combination approaches to robust speech recognition,
=95 datasets, toolboxes and other resources for multisource speech =
separation and recognition.

SUBMISSION INSTRUCTIONS:
Manuscript submissions shall be made through the Elsevier Editorial =
System (EES) at
http://ees.elsevier.com/csl/
Once logged in, click on =93Submit New Manuscript=94 then select =
=93Special Issue: Multisource Environments=94 in the =93Choose Article =
Type=94 dropdown menu.

IMPORTANT DATES:
November 30, 2011: Paper submission
March 30, 2012: First review
May 30, 2012: Revised submission
July 30, 2012: Second review
August 30, 2012: Camera-ready submission

We are looking forward to your submission!

Jon Barker, University of Sheffield, UK
Emmanuel Vincent, INRIA, France

---=20

--Apple-Mail=_EDC2B160-FC49-4860-979B-9662B080E0E5
Content-Transfer-Encoding: quoted-printable
Content-Type: text/html;
charset=windows-1252

<html><head></head><body style=3D"word-wrap: break-word; =
-webkit-nbsp-mode: space; -webkit-line-break: after-white-space; =
">[Apologies for multiple =
postings]<div> </div><div> +++++++++++++++++++++++++++++++++++++++=
++++</div><div> </div>      COMPUTER SPEECH AND =
LANGUAGE       <a =
href="" href="http://www.elsevier.com/locate/csl" target="_blank">http://www.elsevier.com/locate/csl">http://www.elsevier.com/locate=
/csl</a>       Special issue on<div>    =
  SPEECH SEPARATION AND RECOGNITION IN MULTISOURCE =
ENVIRONMENTS       Submission Deadline: =
 NOVEMBER 30, =
2011</div><div> +++++++++++++++++++++++++++++++++++++++++++ > of the chief difficulties of building distant-microphone speech =
recognition systems for use in everyday applications is that the noise =
background is typically `multisource'. A speech recognition system =
designed to operate in a family home, for example, must contend with =
competing noise from televisions and radios, children playing, vacuum =
cleaners, and outdoors noises from open windows. Despite their =
complexity, such environments contain structure that can be learnt and =
exploited using advanced source separation, machine learning and speech =
recognition techniques such as those presented at the 1st International =
Workshop on Machine Listening in Multisource Environments (CHiME =
2011). <a =
href="" href="http://spandh.dcs.shef.ac.uk/projects/chime/workshop/" target="_blank">http://spandh.dcs.shef.ac.uk/projects/chime/workshop/">http://span=
dh.dcs.shef.ac.uk/projects/chime/workshop/</a> This special issue =
solicits papers describing advances in speech separation and recognition =
in multisource noise environments, including theoretical developments, =
algorithms or systems. Examples of topics relevant to the special =
issue include: =95 multiple speaker localization, beamforming and =
source separation, =95 hearing inspired approaches to multisource =
processing, =95 background noise tracking and modelling, =95 =
noise-robust speech decoding, =95 model combination approaches to =
robust speech recognition, =95 datasets, toolboxes and other =
resources for multisource speech separation and =
recognition. SUBMISSION INSTRUCTIONS: Manuscript =
submissions shall be made through the Elsevier Editorial System (EES) =
at <a =
href="" href="http://ees.elsevier.com/csl/" target="_blank">http://ees.elsevier.com/csl/">http://ees.elsevier.com/csl/</a> =
Once logged in, click on =93Submit New Manuscript=94 then select =
=93Special Issue: Multisource Environments=94 in the =93Choose Article =
Type=94 dropdown menu. IMPORTANT DATES: November 30, 2011: =
Paper submission March 30, 2012: First review May 30, 2012: =
Revised submission July 30, 2012: Second review August 30, 2012: =
Camera-ready submission We are looking forward to your =
submission! </div><div> </div><div> </div><div>Jon Barker, =
University of Sheffield, UK Emmanuel Vincent, INRIA, =
France </div><div>--- <div><span class=3D"Apple-style-span" =
style=3D"border-collapse: separate; color: rgb(0, 0, 0); font-family: =
Helvetica; font-size: medium; font-style: normal; font-variant: normal; =
font-weight: normal; letter-spacing: normal; line-height: normal; =
orphans: 2; text-indent: 0px; text-transform: none; white-space: normal; =
widows: 2; word-spacing: 0px; -webkit-border-horizontal-spacing: 0px; =
-webkit-border-vertical-spacing: 0px; =
-webkit-text-decorations-in-effect: none; -webkit-text-size-adjust: =
auto; -webkit-text-stroke-width: 0px; "><span class=3D"Apple-style-span" =
style=3D"border-collapse: separate; color: rgb(0, 0, 0); font-family: =
Helvetica; font-size: medium; font-style: normal; font-variant: normal; =
font-weight: normal; letter-spacing: normal; line-height: normal; =
orphans: 2; text-indent: 0px; text-transform: none; white-space: normal; =
widows: 2; word-spacing: 0px; -webkit-border-horizontal-spacing: 0px; =
-webkit-border-vertical-spacing: 0px; =
-webkit-text-decorations-in-effect: none; -webkit-text-size-adjust: =
auto; -webkit-text-stroke-width: 0px; "><div style=3D"word-wrap: =
break-word; -webkit-nbsp-mode: space; -webkit-line-break: =
after-white-space; "></div></div></div><div>
<span class=3D"Apple-style-span" style=3D"border-collapse: separate; =
color: rgb(0, 0, 0); font-family: Helvetica; font-size: medium; =
font-style: normal; font-variant: normal; font-weight: normal; =
letter-spacing: normal; line-height: normal; orphans: 2; text-align: =
auto; text-indent: 0px; text-transform: none; white-space: normal; =
widows: 2; word-spacing: 0px; -webkit-border-horizontal-spacing: 0px; =
-webkit-border-vertical-spacing: 0px; =
-webkit-text-decorations-in-effect: none; -webkit-text-size-adjust: =
auto; -webkit-text-stroke-width: 0px; "><span class=3D"Apple-style-span" =
style=3D"border-collapse: separate; color: rgb(0, 0, 0); font-family: =
Helvetica; font-size: medium; font-style: normal; font-variant: normal; =
font-weight: normal; letter-spacing: normal; line-height: normal; =
orphans: 2; text-indent: 0px; text-transform: none; white-space: normal; =
widows: 2; word-spacing: 0px; -webkit-border-horizontal-spacing: 0px; =
-webkit-border-vertical-spacing: 0px; =
-webkit-text-decorations-in-effect: none; -webkit-text-size-adjust: =
auto; -webkit-text-stroke-width: 0px; "><div style=3D"word-wrap: =
break-word; -webkit-nbsp-mode: space; -webkit-line-break: =
after-white-space; =
"><div> </div></div></div></body></html>=

--Apple-Mail=_EDC2B160-FC49-4860-979B-9662B080E0E5--

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

Date: Mon, 17 Oct 2011 09:57:17 -0400
From: Patrick Zurek <pat@xxxxxxxx>
Subject: Audio Glitch in Matlab

This is a multi-part message in MIME format.
--------------030103020706040808060701
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Content-Transfer-Encoding: 7bit

I'm writing to notify list readers of a problem playing audio using Matlab.

The problem is that brief signals are truncated, and it happens using
any of the common commands for playing audio (wavplay, sound, and the
play method of the audioplayer object).

I can't specify the exact conditions under which the truncation occurs.
However, with a sample rate of 44.1 kHz, signals shorter than about 500
msec are truncated. I haven't looked much at other sample rates.

A simple work-around for the problem is to pad the end of the signal
with a sufficient number of zeros that truncation occurs during the zero
segment. I've found that at least 2000 zeros need to be added to assure
no truncation of a 10-msec signal (with a sample rate of 44.1kHz).

I've brought this problem to the attention of The Mathworks. They
confirmed the problem, which they attribute to a bug in their driver.

The Mathworks also informed me that the problem has been solved in their
latest release (R2011b) for playing using audioplayer, but not
necessarily for the other audio commands. I've confirmed this in very
limited tests.

The following is a piece of code that you can use to observe the
truncation. It creates a 100-msec, 1-kHz sine wave, applies a hanning
window, and then plays it first with zero-padding and then without. You
should be able to hear the click at the end of the second tone, which is
not present on the first. If not, you can see it on an oscilloscope.

%%%%%%%%%%%%%%%%%%%%
fs = 44100;
f = 1000;
T = 0.1;
nPad = 2000;

nS = round(fs*T);

y = sin(2.*pi*f/fs*(1:nS)');
w = .5*(1 - cos(2*pi*(1:nS)'/(nS+1)));
y = w.*y;
yPad = [y; zeros(nPad,1)];

wavplay(yPad, fs, 'sync')
pause(0.5)
wavplay(y, fs, 'sync')
%%%%%%%%%%%%%%%%%%%%%

--
Patrick M. Zurek
President

Sensimetrics Corporation
14 Summer St.
Suite 403
Malden, MA 02148
Tel: 781-399-0858 x237
Fax: 781-399-0853
email: pat@xxxxxxxx
web: www.sens.com

--------------030103020706040808060701
Content-Type: text/html; charset=ISO-8859-1
Content-Transfer-Encoding: 7bit

<html>
<head>

<meta http-equiv="content-type" content="text/html; charset=ISO-8859-1">
</head>
<body bgcolor="#FFFFFF" text="#000000">
I'm writing to notify list readers of a problem
playing audio using Matlab. 
 
The problem is that brief signals are truncated, and it happens
using any of the common commands for playing audio (wavplay,
sound, and the play method of the audioplayer object). 
 
I can't specify the exact conditions under which the truncation
occurs. However, with a sample rate of 44.1 kHz, signals shorter
than about 500 msec are truncated. I haven't looked much at other
sample rates. 
 
A simple work-around for the problem is to pad the end of the
signal with a sufficient number of zeros that truncation occurs
during the zero segment. I've found that at least 2000 zeros need
to be added to assure no truncation of a 10-msec signal (with a
sample rate of 44.1kHz). 
 
I've brought this problem to the attention of The Mathworks. They
confirmed the problem, which they attribute to a bug in their
driver. 
 
The Mathworks also informed me that the problem has been solved in
their latest release (R2011b) for playing using audioplayer, but
not necessarily for the other audio commands. I've confirmed this
in very limited tests. 
 
The following is a piece of code that you can use to observe the
truncation. It creates a 100-msec, 1-kHz sine wave, applies a
hanning window, and then plays it first with zero-padding and then
without. You should be able to hear the click at the end of the
second tone, which is not present on the first. If not, you can
see it on an oscilloscope. 
 
%%%%%%%%%%%%%%%%%%%% 
fs = 44100; 
f = 1000; 
T = 0.1; 
nPad = 2000; 
 
nS = round(fs*T); 
 
y = sin(2.*pi*f/fs*(1:nS)'); 
w = .5*(1 - cos(2*pi*(1:nS)'/(nS+1))); 
y = w.*y; 
yPad = [y; zeros(nPad,1)]; 
 
wavplay(yPad, fs, 'sync') 
pause(0.5) 
wavplay(y, fs, 'sync') 
%%%%%%%%%%%%%%%%%%%%% 
<pre class="moz-signature" cols="72">--
Patrick M. Zurek
President

Sensimetrics Corporation
14 Summer St.
Suite 403
Malden, MA 02148
Tel: 781-399-0858 x237
Fax: 781-399-0853
email: <a class="moz-txt-link-abbreviated" href="" href="mailto:pat@xxxxxxxx">pat@xxxxxxxx">pat@xxxxxxxx</a>
web: <a class="moz-txt-link-abbreviated" href="" href="http://www.sens.com" target="_blank">http://www.sens.com">www.sens.com</a></pre>
</body>
</html>

--------------030103020706040808060701--

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

Date: Mon, 17 Oct 2011 10:35:49 -0400
From: Brian FG Katz <brian.katz@xxxxxxxx>
Subject: Re: Audio Glitch in Matlab

This is a multipart message in MIME format.

------=_NextPart_000_0084_01CC8CB8.8AAFF440
Content-Type: text/plain;
charset="iso-8859-1"
Content-Transfer-Encoding: quoted-printable

This bug is quite present in Windows. The solution is to not use the =
default
system driver, but an ASIO supported soundcard. This is also recommended =
for
any sync play/rec situations, as the default Windows driver does not =
assure
good or repeatable synchronization.=20

=20

-Brian FG Katz

--

Brian FG Katz, Ph.D

Audio & Acoustique

LIMSI-CNRS

BP 133

F91403 Orsay

France

tel. (+33) 01 69 85 81 55

fax. (+33) 01.69.85.80.88

e-mail <mailto:Brian.Katz@xxxxxxxx> Brian.Katz@xxxxxxxx <
<mailto:Brian.Katz@xxxxxxxx> mailto:Brian.Katz@xxxxxxxx>

web_theme: <http://www.limsi.fr/Scientifique/aa/thmsonesp/>
http://www.limsi.fr/Scientifique/aa/thmsonesp/

web_group: <http://www.limsi.fr/Scientifique/aa/>
http://www.limsi.fr/Scientifique/aa/

=20

=20

=20

De : AUDITORY - Research in Auditory Perception
[mailto:AUDITORY@xxxxxxxxxxxxxxx] De la part de Patrick Zurek
Envoy=E9 : lundi 17 octobre 2011 09:57
=C0 : AUDITORY@xxxxxxxxxxxxxxx
Objet : [AUDITORY] Audio Glitch in Matlab

=20

I'm writing to notify list readers of a problem playing audio using =
Matlab.=20

The problem is that brief signals are truncated, and it happens using =
any of
the common commands for playing audio (wavplay, sound, and the play =
method
of the audioplayer object).

I can't specify the exact conditions under which the truncation occurs.
However, with a sample rate of 44.1 kHz, signals shorter than about 500 =
msec
are truncated. I haven't looked much at other sample rates.

A simple work-around for the problem is to pad the end of the signal =
with a
sufficient number of zeros that truncation occurs during the zero =
segment.
I've found that at least 2000 zeros need to be added to assure no =
truncation
of a 10-msec signal (with a sample rate of 44.1kHz).

I've brought this problem to the attention of The Mathworks. They =
confirmed
the problem, which they attribute to a bug in their driver.=20

The Mathworks also informed me that the problem has been solved in their
latest release (R2011b) for playing using audioplayer, but not =
necessarily
for the other audio commands. I've confirmed this in very limited tests. =

The following is a piece of code that you can use to observe the =
truncation.
It creates a 100-msec, 1-kHz sine wave, applies a hanning window, and =
then
plays it first with zero-padding and then without. You should be able to
hear the click at the end of the second tone, which is not present on =
the
first. If not, you can see it on an oscilloscope.

%%%%%%%%%%%%%%%%%%%%
fs =3D 44100;
f =3D 1000;=20
T =3D 0.1;
nPad =3D 2000;

nS =3D round(fs*T);

y =3D sin(2.*pi*f/fs*(1:nS)');
w =3D .5*(1 - cos(2*pi*(1:nS)'/(nS+1)));
y =3D w.*y;
yPad =3D [y; zeros(nPad,1)];

wavplay(yPad, fs, 'sync')
pause(0.5)
wavplay(y, fs, 'sync')
%%%%%%%%%%%%%%%%%%%%%

--=20
Patrick M. Zurek
President=20
=20
Sensimetrics Corporation
14 Summer St.
Suite 403
Malden, MA 02148
Tel: 781-399-0858 x237
Fax: 781-399-0853
email: pat@xxxxxxxx
web: www.sens.com

------=_NextPart_000_0084_01CC8CB8.8AAFF440
Content-Type: text/html;
charset="iso-8859-1"
Content-Transfer-Encoding: quoted-printable

<META HTTP-EQUIV=3D"Content-Type" CONTENT=3D"text/html; =
charset=3Diso-8859-1">
<html xmlns:v=3D"urn:schemas-microsoft-com:vml" =
xmlns:o=3D"urn:schemas-microsoft-com:office:office" =
xmlns:w=3D"urn:schemas-microsoft-com:office:word" =
xmlns:m=3D"http://schemas.microsoft.com/office/2004/12/omml" =
xmlns=3D"http://www.w3.org/TR/REC-html40"><head><meta name=3DGenerator =
content=3D"Microsoft Word 14 (filtered medium)"><style></style></head><body bgcolor=3Dwhite =
lang=3DEN-US link=3Dblue vlink=3Dpurple><div class=3DWordSection1>This bug is quite present in Windows. The solution is to not use the =
default system driver, but an ASIO supported soundcard. This is also =
recommended for any sync play/rec situations, as the default Windows =
driver does not assure good or repeatable synchronization. =
<o:p></o:p><o:p> </o:p>-Brian FG Katz<o:p></o:p><div>--<o:p></o:p>Brian FG Katz, Ph.D<o:p></o:p>Audio & Acoustique<o:p></o:p>LIMSI-CNRS<o:p></o:p>BP 133<o:p></o:p>F91403 Orsay<o:p></o:p>France<o:p></o:p>tel. (+33) 01 69 85 81 55<o:p></o:p>fax. (+33) 01.69.85.80.88<o:p></o:p>e-mail <a href="" href="mailto:Brian.Katz@xxxxxxxx">Brian.Katz@xxxxxxxx">Brian.Katz@xxxxxxxx</a> <<a href="" href="mailto:Brian.Katz@xxxxxxxx">Brian.Katz@xxxxxxxx">mailto:Brian.Katz@xxxxxxxx</a>><o:p></o:p>web_theme: <a href="" href="http://www.limsi.fr/Scientifique/aa/thmsonesp/" target="_blank">http://www.limsi.fr/Scientifique/aa/thmsonesp/">http://www.limsi.fr/Scientifique/aa/thmsonesp/</span=
></a><o:p></o:p>web_group: <a href="" href="http://www.limsi.fr/Scientifique/aa/" target="_blank">http://www.limsi.fr/Scientifique/aa/">http://www.limsi.fr/Scientifique/aa/</a></spa=
n><o:p></o:p><o:p> </o:p><o:p> </o:p></div><o:p> </o:p><div><div =
style=3D'border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0cm =
0cm 0cm'>De : AUDITORY - Research in Auditory Perception =
[mailto:AUDITORY@xxxxxxxxxxxxxxx] De la part de Patrick =
Zurek Envoy=E9 : lundi 17 octobre 2011 =
09:57 =C0 : =
AUDITORY@xxxxxxxxxxxxxxx Objet : [AUDITORY] Audio Glitch =
in Matlab<o:p></o:p></div></div><o:p> </o:p>I'm writing to notify list =
readers of a problem playing audio using Matlab. The problem is =
that brief signals are truncated, and it happens using any of the common =
commands for playing audio (wavplay, sound, and the play method of the =
audioplayer object). I can't specify the exact conditions under =
which the truncation occurs. However, with a sample rate of 44.1 kHz, =
signals shorter than about 500 msec are truncated. I haven't looked much =
at other sample rates. A simple work-around for the problem is to =
pad the end of the signal with a sufficient number of zeros that =
truncation occurs during the zero segment. I've found that at least 2000 =
zeros need to be added to assure no truncation of a 10-msec signal (with =
a sample rate of 44.1kHz). I've brought this problem to the =
attention of The Mathworks. They confirmed the problem, which they =
attribute to a bug in their driver. The Mathworks also informed =
me that the problem has been solved in their latest release (R2011b) for =""> playing using audioplayer, but not necessarily for the other audio =
commands. I've confirmed this in very limited tests. The =
following is a piece of code that you can use to observe the truncation. =
It creates a 100-msec, 1-kHz sine wave, applies a hanning window, and =
then plays it first with zero-padding and then without. You should be =
able to hear the click at the end of the second tone, which is not =
present on the first. If not, you can see it on an =
oscilloscope. %%%%%%%%%%%%%%%%%%%% fs =3D 44100; f =3D =
1000; T =3D 0.1; nPad =3D 2000; nS =3D =
round(fs*T); y =3D sin(2.*pi*f/fs*(1:nS)'); w =3D .5*(1 - =
cos(2*pi*(1:nS)'/(nS+1))); y =3D w.*y; yPad =3D [y; =
zeros(nPad,1)]; wavplay(yPad, fs, =
'sync') pause(0.5) wavplay(y, fs, =
'sync') %%%%%%%%%%%%%%%%%%%%% <o:p></o:p><pre>-- =
<o:p></o:p></pre><pre>Patrick M. Zurek<o:p></o:p></pre><pre>President =
<o:p></o:p></pre><pre><o:p> </o:p></pre><pre>Sensimetrics =
Corporation<o:p></o:p></pre><pre>14 Summer =
St.<o:p></o:p></pre><pre>Suite 403<o:p></o:p></pre><pre>Malden, MA =
02148<o:p></o:p></pre><pre>Tel: 781-399-0858 =
x237<o:p></o:p></pre><pre>Fax: 781-399-0853<o:p></o:p></pre><pre>email: =
<a =
href="" href="mailto:pat@xxxxxxxx">pat@xxxxxxxx">pat@xxxxxxxx</a><o:p></o:p></pre><pre>web: =
<a =
href="" href="http://www.sens.com" target="_blank">http://www.sens.com">www.sens.com</a><o:p></o:p></pre></div></bod=
y></html>
------=_NextPart_000_0084_01CC8CB8.8AAFF440--

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

Date: Mon, 17 Oct 2011 11:28:33 -0400
From: Joachim Thiemann <joachim.thiemann@xxxxxxxxx>
Subject: Re: Audio Glitch in Matlab

On Mon, Oct 17, 2011 at 09:57, Patrick Zurek <pat@xxxxxxxx> wrote:
> I'm writing to notify list readers of a problem playing audio using Matlab.

I don't know if the bug you're referring to is Windows-specific; but
the "sound" command on Linux used to have ... issues. (possibly
related to the JVM and the OSS/ALSA/whatever is used now transition)

I wrote a small almost trivial workaround (see
http://signalsprocessed.blogspot.com/2011/02/playing-sounds-from-matlab-on-unix.html)
that would simply write the sound to disk then play it from there:

function [ ] = usound( w, fs )
%USOUND Plays sound on ALSA-based linux machines or macs

if nargin < 2
fs = 16000;
end

filename = ['/tmp/' getenv('USER') '_matplay.wav'];
wavwrite( w, fs, filename );
if ismac
eval(['!afplay ' filename ' &']);
else
eval(['!aplay ' filename ' &']);
end

On a modern machine, the overhead is not perceptible: /tmp should be
in RAM anyways.

Note this also doesn't block, so you can continue working while the
sound is playing (IIRC - this code is a bit old :-)

Joe.

--
Joachim Thiemann :: http://www.tsp.ece.mcgill.ca/~jthiem1

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

Date: Mon, 17 Oct 2011 17:52:09 +0200
From: "Jelfs, Sam" <sam.jelfs@xxxxxxxxxxx>
Subject: Re: Audio Glitch in Matlab

--_000_E4FB19A270B2AE4E99E35D8BF51CEA3FC8FD0DCEFCNLCLUEXM03con_
Content-Type: text/plain; charset="iso-8859-1"
Content-Transfer-Encoding: quoted-printable

It is also possible to use PortAudio / pa_wavplay to make use of the ASIO4A=
LL drivers with existing non-asio hardware.

http://www.portaudio.com/
http://www.mathworks.com/matlabcentral/fileexchange/4017
http://www.asio4all.com/

Sam Jelfs

From: AUDITORY - Research in Auditory Perception [mailto:AUDITORY@xxxxxxxxx=
ILL.CA] On Behalf Of Brian FG Katz
Sent: Monday 17 October 2011 16:36
To: AUDITORY@xxxxxxxxxxxxxxx
Subject: Re: [AUDITORY] Audio Glitch in Matlab

This bug is quite present in Windows. The solution is to not use the defaul=
t system driver, but an ASIO supported soundcard. This is also recommended =
for any sync play/rec situations, as the default Windows driver does not as=
sure good or repeatable synchronization.

-Brian FG Katz
--
Brian FG Katz, Ph.D
Audio & Acoustique
LIMSI-CNRS
BP 133
F91403 Orsay
France
tel. (+33) 01 69 85 81 55
fax. (+33) 01.69.85.80.88
e-mail Brian.Katz@xxxxxxxx<mailto:Brian.Katz@xxxxxxxx> <mailto:Brian.Katz@l=
imsi.fr>
web_theme: http://www.limsi.fr/Scientifique/aa/thmsonesp/
web_group: http://www.limsi.fr/Scientifique/aa/

De : AUDITORY - Research in Auditory Perception [mailto:AUDITORY@xxxxxxxxxx=
LL.CA] De la part de Patrick Zurek
Envoy=E9 : lundi 17 octobre 2011 09:57
=C0 : AUDITORY@xxxxxxxxxxxxxxx
Objet : [AUDITORY] Audio Glitch in Matlab

I'm writing to notify list readers of a problem playing audio using Matlab.

The problem is that brief signals are truncated, and it happens using any o=
f the common commands for playing audio (wavplay, sound, and the play metho=
d of the audioplayer object).

I can't specify the exact conditions under which the truncation occurs. How=
ever, with a sample rate of 44.1 kHz, signals shorter than about 500 msec a=
re truncated. I haven't looked much at other sample rates.

A simple work-around for the problem is to pad the end of the signal with a=
sufficient number of zeros that truncation occurs during the zero segment.=
I've found that at least 2000 zeros need to be added to assure no truncati=
on of a 10-msec signal (with a sample rate of 44.1kHz).

I've brought this problem to the attention of The Mathworks. They confirmed=
the problem, which they attribute to a bug in their driver.

The Mathworks also informed me that the problem has been solved in their la=
test release (R2011b) for playing using audioplayer, but not necessarily fo=
r the other audio commands. I've confirmed this in very limited tests.

The following is a piece of code that you can use to observe the truncation=
. It creates a 100-msec, 1-kHz sine wave, applies a hanning window, and the=
n plays it first with zero-padding and then without. You should be able to =
hear the click at the end of the second tone, which is not present on the f=
irst. If not, you can see it on an oscilloscope.

%%%%%%%%%%%%%%%%%%%%
fs =3D 44100;
f =3D 1000;
T =3D 0.1;
nPad =3D 2000;

nS =3D round(fs*T);

y =3D sin(2.*pi*f/fs*(1:nS)');
w =3D .5*(1 - cos(2*pi*(1:nS)'/(nS+1)));
y =3D w.*y;
yPad =3D [y; zeros(nPad,1)];

wavplay(yPad, fs, 'sync')
pause(0.5)
wavplay(y, fs, 'sync')
%%%%%%%%%%%%%%%%%%%%%

--

Patrick M. Zurek

President

Sensimetrics Corporation

14 Summer St.

Suite 403

Malden, MA 02148

Tel: 781-399-0858 x237

Fax: 781-399-0853

email: pat@xxxxxxxx<mailto:pat@xxxxxxxx>

web: www.sens.com<http://www.sens.com>

________________________________
The information contained in this message may be confidential and legally p=
rotected under applicable law. The message is intended solely for the addre=
ssee(s). If you are not the intended recipient, you are hereby notified tha=
t any use, forwarding, dissemination, or reproduction of this message is st=
rictly prohibited and may be unlawful. If you are not the intended recipien=
t, please contact the sender by return e-mail and destroy all copies of the=
original message.

--_000_E4FB19A270B2AE4E99E35D8BF51CEA3FC8FD0DCEFCNLCLUEXM03con_
Content-Type: text/html; charset="iso-8859-1"
Content-Transfer-Encoding: quoted-printable

<html>
<head>
<meta http-equiv=3D"Content-Type" content=3D"text/html; charset=3Diso-8859-=
1">
<meta name=3D"Generator" content=3D"Microsoft Word 12 (filtered medium)">
<style></style>
</head>
<body bgcolor=3D"white" lang=3D"EN-US" link=3D"blue" vlink=3D"purple">
<div class=3D"WordSection1">
It is also possible to us=
e PortAudio / pa_wavplay to make use of the ASIO4ALL drivers with existing =
non-asio hardware.<o:p></o:p>
<o:p> </o:p><=
/p>
<a href="" href="http://www.portaudio.com/" target="_blank">http://www.portaudio.com/">http://www.por=
taudio.com/</a><o:p></o:p>
<a href="" href="http://www.mathworks.com/matlabcentral/fi= leexchange/4017" target="_blank">http://www.mathworks.com/matlabcentral/fi=
leexchange/4017">http://www.mathworks.com/matlabcentral/fileexchange/4017</=
a><o:p></o:p>
<a href="" href="http://www.asio4all.com/" target="_blank">http://www.asio4all.com/">http://www.asio=
4all.com/</a><o:p></o:p>
<o:p> </o:p><=
/p>
<o:p> </o:p><=
/p>
Sam Jelfs<o:p></o:p></spa=
n>
<o:p> </o:p><=
/p>
<div>
<div style=3D"border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0cm =
0cm 0cm">
From:<spa=
n style=3D"font-size:10.0pt;font-family:"Tahoma","sans-serif=
";color:windowtext"> AUDITORY - Research in Auditory Perception [mailt=
o:AUDITORY@xxxxxxxxxxxxxxx]
On Behalf Of Brian FG Katz 
Sent: Monday 17 October 2011 16:36 
To: AUDITORY@xxxxxxxxxxxxxxx 
Subject: Re: [AUDITORY] Audio Glitch in Matlab<o:p></o:p>
</div>
</div>
<o:p> </o:p>
This bug is quite present=
in Windows. The solution is to not use the default system driver, but an A=
SIO supported soundcard. This is also recommended for any
sync play/rec situations, as the default Windows driver does not assure go=
od or repeatable synchronization.
<o:p></o:p>
<o:p> </o:p><=
/p>
-Brian FG Katz<o:p></o:p>=

<div>
--<o:p></o:p></=
span>
Brian FG Katz, =
Ph.D<o:p></o:p>
Audio & Aco=
ustique<o:p></o:p>
LIMSI-CNRS<o:p></o:p></span=
>
BP 133<o:p></o:p></p=
>
F91403 Orsay<o:p></o:p></sp=
an>
France<o:p></o:p></p=
>
tel. (+33) 01 69 85 81 =
55<o:p></o:p>
fax. (+33) 01.69.85.80.=
88<o:p></o:p>
e-mail
<a href="" href="mailto:Brian.Katz@li">Brian.Katz@li=
msi.fr">Brian.Katz@xxxxxxxx</a>
<<a href="" href="mailto:Brian.Ka">Brian.Ka=
tz@xxxxxxxx">mailto:Brian.Katz@xxxxxxxx</a></sp=
an>><o:p></o:p>
web_theme:
<a href="" href="http://www.limsi.fr/= Scientifique/aa/thmsonesp/" target="_blank">http://www.limsi.fr/=
Scientifique/aa/thmsonesp/">http://www.limsi.fr/Scient=
ifique/aa/thmsonesp/</a><o:p></o:p><=
/span>
web_group:
<a href="" href="http://www.limsi.fr/= Scientifique/aa/" target="_blank">http://www.limsi.fr/=
Scientifique/aa/">http://www.limsi.fr/Scientifique/aa/=
</a><o:p></o:p>
<o:p> </o:p></p=
>
<o:p> </o:p></p=
>
</div>
<o:p> </o:p><=
/p>
<div>
<div style=3D"border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0cm =
0cm 0cm">
De =
: AUDITORY - Research i=
n Auditory Perception
[mailto:AUDITORY@xxxxxxxxxxxxxxx] De la part de Patrick Zurek 
Envoy=E9 : lundi 17 octobre 2011 09:57 
=C0 : AUDITORY@xxxxxxxxxxxxxxx 
Objet : [AUDITORY] Audio Glitch in Matlab<o:p></o:p>
</div>
</div>
<o:p> </o:p>
I'm writing to notify lis=
t readers of a problem playing audio using Matlab.
 
 
The problem is that brief signals are truncated, and it happens using any o=
f the common commands for playing audio (wavplay, sound, and the play metho=
d of the audioplayer object). 
 
I can't specify the exact conditions under which the truncation occurs. How=
ever, with a sample rate of 44.1 kHz, signals shorter than about 500 msec a=
re truncated. I haven't looked much at other sample rates. 
 
A simple work-around for the problem is to pad the end of the signal with a=
sufficient number of zeros that truncation occurs during the zero segment.=
I've found that at least 2000 zeros need to be added to assure no truncati=
on of a 10-msec signal (with a sample
rate of 44.1kHz). 
 
I've brought this problem to the attention of The Mathworks. They confirmed=
the problem, which they attribute to a bug in their driver.
 
 
The Mathworks also informed me that the problem has been solved in their la=
test release (R2011b) for playing using audioplayer, but not necessarily fo=
r the other audio commands. I've confirmed this in very limited tests.
 
 
The following is a piece of code that you can use to observe the truncation=
. It creates a 100-msec, 1-kHz sine wave, applies a hanning window, and the=
n plays it first with zero-padding and then without. You should be able to =
hear the click at the end of the
second tone, which is not present on the first. If not, you can see it on =
an oscilloscope. 
 
%%%%%%%%%%%%%%%%%%%% 
fs =3D 44100; 
f =3D 1000; 
T =3D 0.1; 
nPad =3D 2000; 
 
nS =3D round(fs*T); 
 
y =3D sin(2.*pi*f/fs*(1:nS)'); 
w =3D .5*(1 - cos(2*pi*(1:nS)'/(nS+1))); 
y =3D w.*y; 
yPad =3D [y; zeros(nPad,1)]; 
 
wavplay(yPad, fs, 'sync') 
pause(0.5) 
wavplay(y, fs, 'sync') 
%%%%%%%%%%%%%%%%%%%%%<o:p></o:p>
<pre>-- <o:p></o:p></pre>
<pre>Patrick M. Zurek<o:p></o:p></pre>
<pre>President <o:p></o:p></pre>
<pre><o:p> </o:p></pre>
<pre>Sensimetrics Corporation<o:p></o:p></pre>
<pre>14 Summer St.<o:p></o:p></pre>
<pre>Suite 403<o:p></o:p></pre>
<pre>Malden, MA 02148<o:p></o:p></pre>
<pre>Tel: 781-399-0858 x237<o:p></o:p></pre>
<pre>Fax: 781-399-0853<o:p></o:p></pre>
<pre>email: <a href="" href="mailto:pat@xxxxxxxx">pat@xxxxxxxx">pat@xxxxxxxx</a><o:p></o:p></pr=
e>
<pre>web: <a href="" href="http://www.sens.com" target="_blank">http://www.sens.com">www.sens.com</a><o:p></o:p></pre>
</div>
 
<hr>
The information contained in=
this message may be confidential and legally protected under applicable la=
w. The message is intended solely for the addressee(s). If you are not the =
intended recipient, you are hereby notified
that any use, forwarding, dissemination, or reproduction of this message i=
s strictly prohibited and may be unlawful. If you are not the intended reci=
pient, please contact the sender by return e-mail and destroy all copies of=
the original message. 

</body>
</html>

--_000_E4FB19A270B2AE4E99E35D8BF51CEA3FC8FD0DCEFCNLCLUEXM03con_--

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

Date: Mon, 17 Oct 2011 17:21:23 +0100
From: Etienne Gaudrain <egaudrain.cam@xxxxxxxxx>
Subject: Re: Audio Glitch in Matlab

--0015175d03cc7857e604af80ffa9
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: quoted-printable

Hi,

We also had some clicking and truncating issues when using directly the
default (WDM) Windows audio drivers.
Like Brian we solved the problem by using ASIO drivers. You can tap directl=
y
into the ASIO drivers from Matlab using the Playrec (
http://www.playrec.co.uk/) toolbox, based on Portaudio (the audio library
behind Audacity).

And most to our astonishment we discovered that we only needed to initializ=
e
the card using Playrec, and then everything was fine even when using the
standard Matlab functions (sound, audioplay...).

So basically, we do:
playrec('init', 44100, 1, -1);

Then we can call sound(x, fs)... etc... with no clicking and no
truncating...

Maybe the ASIO driver sets the card in a state that is more sensible than
the default state set by the WDM, like putting sensible buffer lengths...
something like that.

The trick works on Windows XP with even older versions of Matlab, and with
E-MU and Asus sound cards.
Haven't tried on Windows 7, and this is probably different as the sound
system is different.

-Etienne

--=20
Etienne Gaudrain, PhD
MRC Cognition and Brain Sciences Unit
15 Chaucer Road
Cambridge, CB2 7EF
United-Kingdom
+44 1223 355 294, ext. 645

On 17 October 2011 15:35, Brian FG Katz <brian.katz@xxxxxxxx> wrote:

> This bug is quite present in Windows. The solution is to not use the
> default system driver, but an ASIO supported soundcard. This is also
> recommended for any sync play/rec situations, as the default Windows driv=
er
> does not assure good or repeatable synchronization. ****
>
> ** **
>
> -Brian FG Katz****
>
> --****
>
> Brian FG Katz, Ph.D****
>
> Audio & Acoustique****
>
> LIMSI-CNRS****
>
> BP 133****
>
> F91403 Orsay****
>
> France****
>
> tel. (+33) 01 69 85 81 55****
>
> fax. (+33) 01.69.85.80.88****
>
> e-mail Brian.Katz@xxxxxxxx <mailto:Brian.Katz@xxxxxxxx<Brian.Katz@xxxxxxx=
r>
> >****
>
> web_theme: http://www.limsi.fr/Scientifique/aa/thmsonesp/****
>
> web_group: http://www.limsi.fr/Scientifique/aa/****
>
> ** **
>
> ** **
>
> ** **
>
> *De :* AUDITORY - Research in Auditory Perception [mailto:
> AUDITORY@xxxxxxxxxxxxxxx] *De la part de* Patrick Zurek
> *Envoy=C3=A9 :* lundi 17 octobre 2011 09:57
> *=C3=80 :* AUDITORY@xxxxxxxxxxxxxxx
> *Objet :* [AUDITORY] Audio Glitch in Matlab****
>
> ** **
>
> I'm writing to notify list readers of a problem playing audio using Matla=
b.
>
>
> The problem is that brief signals are truncated, and it happens using any
> of the common commands for playing audio (wavplay, sound, and the play
> method of the audioplayer object).
>
> I can't specify the exact conditions under which the truncation occurs.
> However, with a sample rate of 44.1 kHz, signals shorter than about 500 m=
sec
> are truncated. I haven't looked much at other sample rates.
>
> A simple work-around for the problem is to pad the end of the signal with=
a
> sufficient number of zeros that truncation occurs during the zero segment=
.
> I've found that at least 2000 zeros need to be added to assure no truncat=
ion
> of a 10-msec signal (with a sample rate of 44.1kHz).
>
> I've brought this problem to the attention of The Mathworks. They confirm=
ed
> the problem, which they attribute to a bug in their driver.
>
> The Mathworks also informed me that the problem has been solved in their
> latest release (R2011b) for playing using audioplayer, but not necessaril=
y
> for the other audio commands. I've confirmed this in very limited tests.
>
> The following is a piece of code that you can use to observe the
> truncation. It creates a 100-msec, 1-kHz sine wave, applies a hanning
> window, and then plays it first with zero-padding and then without. You
> should be able to hear the click at the end of the second tone, which is =
not
> present on the first. If not, you can see it on an oscilloscope.
>
> %%%%%%%%%%%%%%%%%%%%
> fs =3D 44100;
> f =3D 1000;
> T =3D 0.1;
> nPad =3D 2000;
>
> nS =3D round(fs*T);
>
> y =3D sin(2.*pi*f/fs*(1:nS)');
> w =3D .5*(1 - cos(2*pi*(1:nS)'/(nS+1)));
> y =3D w.*y;
> yPad =3D [y; zeros(nPad,1)];
>
> wavplay(yPad, fs, 'sync')
> pause(0.5)
> wavplay(y, fs, 'sync')
> %%%%%%%%%%%%%%%%%%%%%
>
> ****
>
> -- ****
>
> Patrick M. Zurek****
>
> President ****
>
> ** **
>
> Sensimetrics Corporation****
>
> 14 Summer St.****
>
> Suite 403****
>
> Malden, MA 02148****
>
> Tel: 781-399-0858 x237****
>
> Fax: 781-399-0853****
>
> email: pat@xxxxxxxx****
>
> web: www.sens.com****
>
>

--0015175d03cc7857e604af80ffa9
Content-Type: text/html; charset=UTF-8
Content-Transfer-Encoding: quoted-printable

Hi,=C2=A0 We also had some clicking and truncating issues when u=
sing directly the default (WDM) Windows audio drivers.=C2=A0 
Like Brian we solved the problem by using ASIO drivers. You can tap directl=
y into the ASIO drivers from Matlab using the Playrec (<a href="" href="http://ww" target="_blank">http://ww=
w.playrec.co.uk/" target=3D"_blank" style=3D"color: rgb(0, 0, 204); ">http:=
//www.playrec.co.uk/</a>) toolbox, based on Portaudio (the audio library be=
hind Audacity).=C2=A0 
<div class=3D"im" style=3D"color: rgb(80, 0, 80); "> And most to our ast=
onishment we discovered that we only needed to initialize the card using Pl=
ayrec, and then everything was fine even when using the standard Matlab fun=
ctions (sound, audioplay...).=C2=A0 
 So basically, we do:=C2=A0 playrec('init', 44100, 1, -1);=C2=
=A0 Then we can call sound(x, fs)... etc... with no clicking and no =
truncating...=C2=A0 Maybe the ASIO driver sets the card in a state t=
hat is more sensible than the default state set by the WDM, like putting se=
nsible buffer lengths... something like that.=C2=A0 
 The trick works on Windows XP with even older versions of Matlab, and w=
ith E-MU and Asus sound cards.=C2=A0 Haven't tried on Windows 7, and=
this is probably different as the sound system is different.=C2=A0 =
-Etienne=C2=A0 
 <div>--=C2=A0 Etienne Gaudrain, PhD MRC Cognition an=
d Brain Sciences Unit 15 Chaucer Road Cambridge, CB2 7EF United-Ki=
ngdom <a href="" value=3D"=
+441223355294" target=3D"_blank" style=3D"color: rgb(0, 0, 204); ">+44 1223=
355 294, ext. 645</a>=C2=A0 
</div><div> </div></div> <div class=3D"gmail_quote">On 17 Octo=
ber 2011 15:35, Brian FG Katz <<a href="" href="mailto:brian">brian=
.katz@xxxxxxxx">brian.katz@xxxxxxxx</a>> wrote: <blockquote cl=
ass=3D"gmail_quote" style=3D"margin:0 0 0 .8ex;border-left:1px #ccc solid;p=
adding-left:1ex;">

<div bgcolor=3D"white" lang=3D"EN-US" link=3D"blue" vlink=3D"purple"><div><=
p class=3D"MsoNormal">This b=
ug is quite present in Windows. The solution is to not use the default syst=
em driver, but an ASIO supported soundcard. This is also recommended for an=
y sync play/rec situations, as the default Windows driver does not assure g=
ood or repeatable synchronization. 
</=
u>=C2=A0-Brian FG Katz<div>
--=
Brian FG Katz, Ph.D
Audio & Acou=
stiqueLIMSI-CNRS
BP 133<=
/p>F9=
1403 OrsayFrance
tel. =
<a href="" value=3D"+33169858155"=
target=3D"_blank">(+33) 01 69 85 81 55</a>
fax. <a href=""> %29%2001.69.85.80.88" value=3D"+33169858088" target=3D"_blank">(+33) 01.69.=
85.80.88</a>e-mail <a href="" href="mailto:Brian.Katz@xxxxxxxx">Brian.Katz@xxxxxxxx" target=
=3D"_blank">Brian.Katz@xxxxxxxx</=
span></a> <=
<a href=""> o:Brian.Katz@xxxxxxxx" target=3D"_blank">mailto:Brian.Katz@xxxxxxxx</a>>
web_t=
heme: <a =
href="" href="http://www.limsi.fr/Scientifique/aa/thmsonesp/" target="_blank">http://www.limsi.fr/Scientifique/aa/thmsonesp/" target=3D"_blank"><=
span lang=3D"EN-US" style=3D"color:blue">http://www.limsi.fr/Scientifique/a=
a/thmsonesp/</a>
web_g=
roup: <a =
href="" href="http://www.limsi.fr/Scientifique/aa/" target="_blank">http://www.limsi.fr/Scientifique/aa/" target=3D"_blank">http://www.limsi.fr/Scientifique/aa/=
</a></s=
pan>
</=
u>=C2=A0=C2=A0</div>=C2=A0</=
span>
<div><div style=3D"border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt=
0cm 0cm 0cm">De=C2=A0: AUDITORY - Research in Auditory Percepti=
on [mailto:<a href="" href="mailto:AUDITORY@xxxxxxxxxxxxxxx">AUDITORY@xxxxxxxxxxxxxxx" target=3D"_blank">AU=
DITORY@xxxxxxxxxxxxxxx</a>] De la part de Patrick Zurek 
Envoy=C3=A9=C2=A0: lundi 17 octobre 2011 09:57 =C3=80=C2=A0:</=
b> <a href="" href="mailto:AUDITORY@xxxxxxxxxxxxxxx">AUDITORY@xxxxxxxxxxxxxxx" target=3D"_blank">AUDITORY@L=
ISTS.MCGILL.CA</a> Objet=C2=A0: [AUDITORY] Audio Glitch in Matlab=

</div></div><div><div></div><div class=3D"h5"></u=
>=C2=A0I'm writing to notify li=
st readers of a problem playing audio using Matlab. The problem is =
that brief signals are truncated, and it happens using any of the common co=
mmands for playing audio (wavplay, sound, and the play method of the audiop=
layer object). 
 I can't specify the exact conditions under which the truncation occ=
urs. However, with a sample rate of 44.1 kHz, signals shorter than about 50=
0 msec are truncated. I haven't looked much at other sample rates. 
 A simple work-around for the problem is to pad the end of the signal wi=
th a sufficient number of zeros that truncation occurs during the zero segm=
ent. I've found that at least 2000 zeros need to be added to assure no =
truncation of a 10-msec signal (with a sample rate of 44.1kHz). 
 I've brought this problem to the attention of The Mathworks. They c=
onfirmed the problem, which they attribute to a bug in their driver. <b=
r>The Mathworks also informed me that the problem has been solved in their =
latest release (R2011b) for playing using audioplayer, but not necessarily =
for the other audio commands. I've confirmed this in very limited tests=
. 
 The following is a piece of code that you can use to observe the trunca=
tion. It creates a 100-msec, 1-kHz sine wave, applies a hanning window, and=
then plays it first with zero-padding and then without. You should be able=
to hear the click at the end of the second tone, which is not present on t=
he first. If not, you can see it on an oscilloscope. 
 %%%%%%%%%%%%%%%%%%%% fs =3D 44100; f =3D 1000; T =3D 0.1; =
nPad =3D 2000; nS =3D round(fs*T); y =3D sin(2.*pi*f/fs*(1:nS=
)'); w =3D .5*(1 - cos(2*pi*(1:nS)'/(nS+1))); y =3D w.*y; =
yPad =3D [y; zeros(nPad,1)]; 
 wavplay(yPad, fs, 'sync') pause(0.5) wavplay(y, fs, '=
sync') %%%%%%%%%%%%%%%%%%%%% <pre>--=
</pre><pre>Patrick M. Zurek</pre><pre>Presiden=
t </pre>
<pre>=C2=A0</pre><pre>Sensimetrics Corporation<=
/pre><pre>14 Summer St.</pre><pre>Suite 403</pr=
e><pre>Malden, MA 02148</pre><pre>Tel: <a href=""> -0858%20x237" value=3D"+17813990858" target=3D"_blank">781-399-0858 x237</a=
></pre>
<pre>Fax: <a href="" value=3D"+17813990853" target=3D"_bl=
ank">781-399-0853</a></pre><pre>email: <a href="" href="mailto:pat@">pat@=
sens.com" target=3D"_blank">pat@xxxxxxxx</a></pre><pre>web: <=
a href="" href="http://www.sens.com" target="_blank">http://www.sens.com" target=3D"_blank">www.sens.com</a>=
</pre>
</div></div></div></div></blockquote></div> 

--0015175d03cc7857e604af80ffa9--

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

End of AUDITORY Digest - 14 Oct 2011 to 17 Oct 2011 - Special issue (#2011-238)
*******************************************************************************

--
Vijaya Kumar Narne PhD,
India

Re: AUDITORY Digest - 14 Oct 2011 to 17 Oct 2011 - Special issue (#2011-238)