Subject: Re: ICA, a key to solve the puzzle of hearing From: Peter Lennox <peter(at)LENNOX01.FREESERVE.CO.UK> Date: Sat, 26 Mar 2005 11:16:16 -0000--=======AVGMAIL-424BA0501F73======= Content-Type: multipart/alternative; boundary="----=_NextPart_000_001B_01C531F5.3A330D60" ------=_NextPart_000_001B_01C531F5.3A330D60 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable >From a limited number of microphones, it is possible to extract more = than this number of signals - that's basically what stereo and = ambisonics (not to mention transaural) does. Using several spaced = capsules (as against coincident or virtually coincident) can work in = higher order ambisonics, theoretically, though there are some 'noise' = issues at present. Whtether the capsules are directional or omni (or 'in = between' - semi-cardioid as used in the SoundField Mic), it's not = necessary to assume that switching between capsules is what you want to = do. - you're actually just looking for a signal that is optimised for a = particular source. By treating your signals in a matrixed fashion, you = can rapidly try out succesions of 'decodes' (and these can have = frequency dependent components, too). Nevertheless, who or what is = steering? - is this a learning algorithm designed to mimic scene = analysis? - it would seem that you need a best-fit explanation for the = entirety of components in a detected sound field, otherwise you'll have = 'bits left over' - isn't that right? regards ppl ----- Original Message -----=20 From: jan schnupp=20 To: AUDITORY(at)LISTS.MCGILL.CA=20 Sent: 25 March 2005 17:43 Subject: Re: ICA, a key to solve the puzzle of hearing On Fri, 25 Mar 2005, Guoping Li wrote: =20 ICA was designed to solve the problem of cocktail party effect using higher order statistical methods. Is it possible that we can use this technique and implement it in the hearing aid or cochlear implant? =20 =20 Toth Laszlo wrote:=20 As far as I remember, when ICA is used for blind signal separation, it needs at least N input signals (for example, from a microphone array) = for extracting N independent components. :( =20 That's true, but there is no reason a priori why one shouldn't build a = device that incorporates dozens of microphone capsules in the users = clothing, and that could separate dozens of different sources. Then = you'd just need a little switch that allows you to quickly scan through = those separated sources to find the one you want to listen to. It = wouldn't be very "biological", but it might nevertheless work quite = well.=20 Jan -------------------------------------------------------- Dr. Jan Schnupp University Laboratory of Physiology St Peter's College Oxford University New Inn Hall Street Parks Road, Oxford OX1 3PT, UK Oxford OX1 2PL Tel (01865) 272513 Tel (01865) 278889 Fax (01865) 272469 -------------------------------------------------------------------------= ----- No virus found in this incoming message. Checked by AVG Anti-Virus. Version: 7.0.308 / Virus Database: 266.8.3 - Release Date: 25/03/05 ------=_NextPart_000_001B_01C531F5.3A330D60 Content-Type: text/html; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"> <HTML><HEAD><TITLE></TITLE> <META http-equiv=3DContent-Type = content=3Dtext/html;charset=3DISO-8859-1> <META content=3D"MSHTML 6.00.2600.0" name=3DGENERATOR> <STYLE></STYLE> </HEAD> <BODY bgColor=3D#ffffff> <DIV><FONT size=3D2>From a limited number of microphones, it is possible = to=20 extract more than this number of signals - that's basically what stereo = and=20 ambisonics (not to mention transaural) does. Using several spaced = capsules (as=20 against coincident or virtually coincident) can work in higher = order=20 ambisonics, theoretically, though there are some 'noise' issues at = present.=20 Whtether the capsules are directional or omni (or 'in between' - = semi-cardioid=20 as used in the SoundField Mic), it's not necessary to assume that = switching=20 between capsules is what you want to do. - you're actually just looking = for a=20 signal that is optimised for a particular source. By treating your = signals in a=20 matrixed fashion, you can rapidly try out succesions of 'decodes' (and = these can=20 have frequency dependent components, too). Nevertheless, who or what is=20 steering? - is this a learning algorithm designed to mimic scene = analysis? - it=20 would seem that you need a best-fit explanation for the entirety of = components=20 in a detected sound field, otherwise you'll have 'bits left over' - = isn't that=20 right?</FONT></DIV> <DIV><FONT size=3D2>regards</FONT></DIV> <DIV><FONT size=3D2>ppl</FONT></DIV> <BLOCKQUOTE=20 style=3D"PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; = BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px"> <DIV style=3D"FONT: 10pt arial">----- Original Message ----- </DIV> <DIV=20 style=3D"BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: = black"><B>From:</B>=20 <A title=3Djan.schnupp(at)PHYSIOL.OX.AC.UK=20 href=3D"mailto:jan.schnupp(at)PHYSIOL.OX.AC.UK">jan schnupp</A> </DIV> <DIV style=3D"FONT: 10pt arial"><B>To:</B> <A = title=3DAUDITORY(at)LISTS.MCGILL.CA=20 href=3D"mailto:AUDITORY(at)LISTS.MCGILL.CA">AUDITORY(at)LISTS.MCGILL.CA</A> = </DIV> <DIV style=3D"FONT: 10pt arial"><B>Sent:</B> 25 March 2005 17:43</DIV> <DIV style=3D"FONT: 10pt arial"><B>Subject:</B> Re: ICA, a key to = solve the=20 puzzle of hearing</DIV> <DIV><BR></DIV><BR> <BLOCKQUOTE = cite=3DmidPine.GSO.4.58.0503251748400.3662(at)orsi.inf.u-szeged.hu=20 type=3D"cite"><PRE wrap=3D"">On Fri, 25 Mar 2005, Guoping Li wrote: </PRE> <BLOCKQUOTE type=3D"cite"><PRE wrap=3D""> ICA was designed to solve = the problem of cocktail party effect using higher order statistical methods. Is it possible that we can use this technique and implement it in the hearing aid or cochlear implant? </PRE></BLOCKQUOTE><PRE wrap=3D""><!----> </PRE></BLOCKQUOTE>Toth Laszlo wrote:=20 <BLOCKQUOTE = cite=3DmidPine.GSO.4.58.0503251748400.3662(at)orsi.inf.u-szeged.hu=20 type=3D"cite"><PRE wrap=3D"">As far as I remember, when ICA is used = for blind signal separation, it needs at least N input signals (for example, from a microphone array) = for extracting N independent components. :( </PRE></BLOCKQUOTE><BR>That's true, but there is no reason a priori = why one=20 shouldn't build a device that incorporates dozens of microphone = capsules in=20 the users clothing, and that could separate dozens of different = sources. Then=20 you'd just need a little switch that allows you to quickly scan = through those=20 separated sources to find the one you want to listen to. It wouldn't = be very=20 "biological", but it might nevertheless work quite well. = <BR><BR>Jan<BR><PRE class=3Dmoz-signature = cols=3D"80">-------------------------------------------------------- Dr. Jan Schnupp University Laboratory of Physiology St Peter's College Oxford University New Inn Hall Street Parks Road, Oxford OX1 3PT, UK Oxford OX1 2PL Tel (01865) 272513 Tel (01865) 278889 Fax (01865) 272469 </PRE> <P> <HR> <P></P>No virus found in this incoming message.<BR>Checked by AVG=20 Anti-Virus.<BR>Version: 7.0.308 / Virus Database: 266.8.3 - Release = Date:=20 25/03/05<BR></BLOCKQUOTE></BODY></HTML> ------=_NextPart_000_001B_01C531F5.3A330D60-- --=======AVGMAIL-424BA0501F73======= Content-Type: text/plain; x-avg=cert; charset=us-ascii Content-Transfer-Encoding: quoted-printable Content-Disposition: inline Content-Description: "AVG certification" No virus found in this outgoing message. Checked by AVG Anti-Virus. Version: 7.0.308 / Virus Database: 266.8.4 - Release Date: 27/03/05 --=======AVGMAIL-424BA0501F73=======--