Subject: Re: High frequency hearing From: =?ISO-8859-1?Q?S=F8ren_Buus?= <buus(at)NEU.EDU> Date: Thu, 7 Nov 2002 10:54:41 -0500--Apple-Mail-2-395222651 Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset=US-ASCII; format=flowed Dear List, I sent the following directly to David, but it appears that it may be of general interest. Several experiments have shown that ultrasound (above 20 kHz) can readily be detected by many listeners, even by some who may have considerable hearing losses at conventional audiometric frequencies. From: Soren Buus <buus(at)ece.neu.edu> Date: Tue Nov 05, 2002 10:43:14 AM US/Eastern To: david(at)robinson.org Subject: Re: High frequency hearing Hi David, You may find the following paper to be of interest: Buus, S., Florentine, M., and Mason, C. R. (1986). "Tuning curves at=20 high frequencies and their relation to the absolute threshold curve," in=20= Auditory Frequency Selectivity, edited by B. C. J. Moore and R. D.=20 Patterson (Plenum, New York), pp. 341-350. In addition, there is a number of articles on perception of=20 ultra-high-frequency (above 20 kHz) sound delivered by bone conduction. One such article is Lenhardt, M. L., Skellett, R., Wang, P., and Clarke, A. M. (1991).=20 "Human ultrasonic speech perception," Science 253, 82-5. Hope this helps. Best wishes, Soren Buus Begin forwarded message: From: Lars Bramsl=F8w <LAB(at)oticon.dk> Date: Thu Nov 07, 2002 10:04:20 AM US/Eastern To: AUDITORY(at)lists.mcgill.ca Subject: Re: High frequency hearing Reply-To: Lars Bramsl=F8w <LAB(at)oticon.dk> And yet we now have audio equipment with 96 kHz sampling - what a = waste! The only evidence I have seen - which as been forwarded by the '96 = kHz' proponents and audio manufacturers are some EEG measurements done on=20= humans exposed to ultrasound, using few subjects. It is a rather indirect=20 method and I don't know if this has been published. The results could be interesting, and like Bob points out the only meaningful way would be to have the object move. This could be done=20= using some kind of moving chair that would circle a small region within the duration of one stimulus. Regards, Lars Bramsl=F8w ----------------------------------------------------- Lars Bramsl=F8w Ph.D., M.Sc.E.E. Audiology Oticon A/S Strandvejen 58 DK - 2900 Hellerup phone: +45 39 13 85 42 fax: +45 39 27 79 00 mailto:lab(at)oticon.dk http://www.oticon.com ----------------------------------------------------- -----Original Message----- From: David Robinson [mailto:david(at)ROBINSON.ORG] Sent: 5. november 2002 15:28 To: AUDITORY(at)LISTS.MCGILL.CA Subject: High frequency hearing I am trying to discover the limits of high frequency hearing in the most sensitive human listeners. The standard MAF curve(s) are of little use because a) The data does not extend to very high frequencies (i.e. it usually stops between 15 and 20 kHz), and b) the data is based on median results. Ideally, I would like real data to confirm the anecdotal evidence that young and/or gifted listeners can hear up to 25kHz (or beyond?). Equal loudness data would be useful too, but the most useful information would be an indication (very very roughly) of the % of listeners of a particular age who can hear a particular frequency at a particular amplitude. Is there anything like this in the published literature? I have looked several times, but everything I find stops at 16kHz! Also, anything other than median results seems very thin on the ground. Thanks in anticipation of any help - any pointers would be very greatfully received! Cheers, David. http://www.David.Robinson.org/ P.S. I can't see the local primary school being too keen to lend out children for a high frequency listening test - is this the reason no one else has studied this? --Apple-Mail-2-395222651 Content-Transfer-Encoding: 7bit Content-Type: text/enriched; charset=US-ASCII Dear List, I sent the following directly to David, but it appears that it may be of general interest. Several experiments have shown that ultrasound (above 20 kHz) can readily be detected by many listeners, even by some who may have considerable hearing losses at conventional audiometric frequencies. From: Soren Buus <<buus(at)ece.neu.edu> Date: Tue Nov 05, 2002 10:43:14 AM US/Eastern To: david(at)robinson.org Subject: Re: High frequency hearing Hi David, You may find the following paper to be of interest: Buus, S., Florentine, M., and Mason, C. R. (1986). "Tuning curves at=20 high frequencies and their relation to the absolute threshold curve," in=20= Auditory Frequency Selectivity, edited by B. C. J. Moore and R. D.=20 Patterson (Plenum, New York), pp. 341-350. In addition, there is a number of articles on perception of=20 ultra-high-frequency (above 20 kHz) sound delivered by bone conduction. One such article is Lenhardt, M. L., Skellett, R., Wang, P., and Clarke, A. M. (1991).=20 "Human ultrasonic speech perception," Science 253, 82-5. Hope this helps. Best wishes, Soren Buus Begin forwarded message: <color><param>0000,0000,DEDE</param>From: Lars Bramsl=F8w <<LAB(at)oticon.dk> Date: Thu Nov 07, 2002 10:04:20 AM US/Eastern To: AUDITORY(at)lists.mcgill.ca Subject: Re: High frequency hearing Reply-To: Lars Bramsl=F8w <<LAB(at)oticon.dk> And yet we now have audio equipment with 96 kHz sampling - what a = </color>waste! <color><param>0000,0000,DEDE</param> The only evidence I have seen - which as been forwarded by the '96 = </color>kHz' <color><param>0000,0000,DEDE</param>proponents and audio manufacturers are some EEG measurements done on=20= </color> <color><param>0000,0000,DEDE</param>humans exposed to ultrasound, using few subjects. It is a rather indirect=20 method and I don't know if this has been published. The results could be interesting, and like Bob points out the only meaningful way would be to have the object move. This could be done=20= </color> <color><param>0000,0000,DEDE</param>using some kind of moving chair that would circle a small region within the duration of one stimulus. Regards, Lars Bramsl=F8w ----------------------------------------------------- Lars Bramsl=F8w Ph.D., M.Sc.E.E. Audiology Oticon A/S Strandvejen 58 DK - 2900 Hellerup phone: +45 39 13 85 42 fax: +45 39 27 79 00 </color><underline><color><param>1A1A,1A1A,FFFF</param>mailto:lab(at)oticon.dk</color></underline><color><param>0000,0000,DEDE</param> </color><underline><color><param>1A1A,1A1A,FFFF</param>http://www.oticon.com</color></underline><color><param>0000,0000,DEDE</param> ----------------------------------------------------- -----Original Message----- From: David Robinson [</color><underline><color><param>1A1A,1A1A,FFFF</param>mailto:david(at)ROBINSON.ORG</color></underline><color><param>0000,0000,DEDE</param>] Sent: 5. november 2002 15:28 To: AUDITORY(at)LISTS.MCGILL.CA Subject: High frequency hearing I am trying to discover the limits of high frequency hearing in the most sensitive human listeners. The standard MAF curve(s) are of little use because a) The data does not extend to very high frequencies (i.e. it usually stops between 15 and 20 kHz), and b) the data is based on median results. Ideally, I would like real data to confirm the anecdotal evidence that young and/or gifted listeners can hear up to 25kHz (or beyond?). Equal loudness data would be useful too, but the most useful information would be an indication (very very roughly) of the % of listeners of a particular age who can hear a particular frequency at a particular amplitude. Is there anything like this in the published literature? I have looked several times, but everything I find stops at 16kHz! Also, anything other than median results seems very thin on the ground. Thanks in anticipation of any help - any pointers would be very greatfully received! Cheers, David. </color><underline><color><param>1A1A,1A1A,FFFF</param>http://www.David.Robinson.org/</color></underline><color><param>0000,0000,DEDE</param> P.S. I can't see the local primary school being too keen to lend out children for a high frequency listening test - is this the reason no one else has studied this? </color> --Apple-Mail-2-395222651--