Subject: Re: TTS as surrogate for noise exposure measurement From: David Mountain <dcm@xxxxxxxx> Date: Wed, 17 Apr 2013 20:17:50 -0400 List-Archive:<http://lists.mcgill.ca/scripts/wa.exe?LIST=AUDITORY>--001a11c2a0f467964e04da978822 Content-Type: text/plain; charset=ISO-8859-1 Since the original question was really about sound levels at the ear drum while wearing headphones, I don't see a straight forward way of getting at this with a cell-phone app since you can't stick the phone in your ear. Perhaps we could come up with simple design for a 2 cc coupler that could couple the headphone to a cell phone microphone.. On Tue, Apr 16, 2013 at 4:01 AM, Andreas Widmann <widmann@xxxxxxxx>wrote: > > Since this is just for "casual" purposes, not research, > > etc, he'd probably be happy with some sort of rule-of-thumb > > metric... > iPhone available from family/friends? The iPhone microphone has a > reputation of being calibrated quite well. There are dozens of dB-meters of > any kind in the App Store. In a German computer journal "Noise Immission > Analyzer" ( > https://itunes.apple.com/de/app/noise-immission-analyzer/id518336921?mt=8) > got quite nice comments recently. > > Not research grade but should be god enough for rule-of-thumb metric. > Best, > Andreas > > Am 15.04.2013 um 15:02 schrieb Bob Masta <audio@xxxxxxxx>: > > > I've been contacted by a young person in Hungary who is > > concerened that his music listening habits may be damaging > > his hearing. He saw that my Daqarta software has a built- > > in SPL meter feature, and he wanted to know how to use it > > to measure the headphone level of his music, so he could > > keep it under 80 dB SPL. > > > > Unfortunately, he says he can't afford a calibrated > > microphone, which would of course be needed for any SPL > > measurements. > > > > Since this is just for "casual" purposes, not research, > > etc, he'd probably be happy with some sort of rule-of-thumb > > metric... but I don't know of any. I'm thinking here of > > non-technical things like they recommend for aerobic > > exercise, such as "walk fast enough so that you can just > > barely carry on a conversation"... only for hearing. > > (Anyone?) > > > > One problem is that I can't think of any household sounds > > with a standard loudness. Another is that if he already > > has some PTS he would get false assurance that his > > listening levels were not too loud. > > > > So my question for the group is about using TTS. The > > beauty of this is that it requires no absolute calibration. > > He could measure his threshold at some specified frequency > > in the morning before he starts his music listening, and > > record the level in dB relative to full scale (whatever it > > might actually be), then repeat it after listening and take > > the difference. He can use Daqarta to do this for free. > > > > I think if he finds *any* shift it means his music is too > > loud, but the converse is probably not true... especially > > if there is already some PTS, which would presumably reduce > > the amount of TTS. True? Any thoughts on this whole > > approach? > > > > I have discarded one possible alternative approach, which > > would be to listen at his usual level, then reduce the > > level until he can just barely hear it and record how much > > reduction that took. The problem with this dB-above- > > threshold measurement is once again that if there is PTS > > his higher threshold would make his music measure softer. > > > > Any other ideas? > > > > Thanks, and best regards, > > > > > > > > > > Bob Masta > > > > D A Q A R T A > > Data AcQuisition And Real-Time Analysis > > www.daqarta.com > > Scope, Spectrum, Spectrogram, Signal Generator > > Science with your sound card! > > > -- David C. Mountain, Ph.D. Professor of Biomedical Engineering Boston University 44 Cummington St. Boston, MA 02215 Email: dcm@xxxxxxxx Website: http://www.bu.edu/hrc/research/laboratories/auditory-biophysics/ Phone: (617) 353-4343 FAX: (617) 353-6766 Office: ERB 413 --001a11c2a0f467964e04da978822 Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Since the original question was really about sound levels at the ear drum w= hile wearing headphones, I don't see a straight forward way of getting = at this with a cell-phone app since you can't stick the phone in your e= ar. =A0Perhaps we could come up with simple design for a 2 cc coupler that = could couple the headphone to a cell phone microphone..<br> <br><div class=3D"gmail_quote">On Tue, Apr 16, 2013 at 4:01 AM, Andreas Wid= mann <span dir=3D"ltr"><<a href=3D"mailto:widmann@xxxxxxxx" target= =3D"_blank">widmann@xxxxxxxx</a>></span> wrote:<br><blockquote cla= ss=3D"gmail_quote" style=3D"margin:0 0 0 .8ex;border-left:1px #ccc solid;pa= dding-left:1ex"> <div class=3D"im">> Since this is just for "casual" purposes, = not research,<br> > etc, he'd probably be happy with some sort of rule-of-thumb<br> > metric...<br> </div>iPhone available from family/friends? The iPhone microphone has a rep= utation of being calibrated quite well. There are dozens of dB-meters of an= y kind in the App Store. In a German computer journal "Noise Immission= Analyzer" (<a href=3D"https://itunes.apple.com/de/app/noise-immission= -analyzer/id518336921?mt=3D8" target=3D"_blank">https://itunes.apple.com/de= /app/noise-immission-analyzer/id518336921?mt=3D8</a>) got quite nice commen= ts recently.<br> <br> Not research grade but should be god enough for rule-of-thumb metric.<br> Best,<br> Andreas<br> <br> Am 15.04.2013 um 15:02 schrieb Bob Masta <<a href=3D"mailto:audio@xxxxxxxx= A.COM">audio@xxxxxxxx</a>>:<br> <div class=3D"HOEnZb"><div class=3D"h5"><br> > I've been contacted by a young person in Hungary who is<br> > concerened that his music listening habits may be damaging<br> > his hearing. =A0He saw that my Daqarta software has a built-<br> > in SPL meter feature, and he wanted to know how to use it<br> > to measure the headphone level of his music, so he could<br> > keep it under 80 dB SPL.<br> ><br> > Unfortunately, he says he can't afford a calibrated<br> > microphone, which would of course be needed for any SPL<br> > measurements.<br> ><br> > Since this is just for "casual" purposes, not research,<br> > etc, he'd probably be happy with some sort of rule-of-thumb<br> > metric... but I don't know of any. =A0I'm thinking here of<br> > non-technical things like they recommend for aerobic<br> > exercise, such as "walk fast enough so that you can just<br> > barely carry on a conversation"... only for hearing.<br> > (Anyone?)<br> ><br> > One problem is that I can't think of any household sounds<br> > with a standard loudness. =A0Another is that if he already<br> > has some PTS he would get false assurance that his<br> > listening levels were not too loud.<br> ><br> > So my question for the group is about using TTS. =A0The<br> > beauty of this is that it requires no absolute calibration.<br> > He could measure his threshold at some specified frequency<br> > in the morning before he starts his music listening, and<br> > record the level in dB relative to full scale (whatever it<br> > might actually be), then repeat it after listening and take<br> > the difference. =A0He can use Daqarta to do this for free.<br> ><br> > I think if he finds *any* shift it means his music is too<br> > loud, but the converse is probably not true... especially<br> > if there is already some PTS, which would presumably reduce<br> > the amount of TTS. =A0True? =A0Any thoughts on this whole<br> > approach?<br> ><br> > I have discarded one possible alternative approach, which<br> > would be to listen at his usual level, then reduce the<br> > level until he can just barely hear it and record how much<br> > reduction that took. =A0The problem with this dB-above-<br> > threshold measurement is once again that if there is PTS<br> > his higher threshold would make his music measure softer.<br> ><br> > Any other ideas?<br> ><br> > Thanks, and best regards,<br> ><br> ><br> ><br> ><br> > Bob Masta<br> ><br> > =A0 =A0 =A0 =A0 =A0 =A0D A Q A R T A<br> > Data AcQuisition And Real-Time Analysis<br> > =A0 =A0 =A0 =A0 =A0 <a href=3D"http://www.daqarta.com" target=3D"_blan= k">www.daqarta.com</a><br> > Scope, Spectrum, Spectrogram, Signal Generator<br> > =A0 =A0Science with your sound card!<br> ><br> </div></div></blockquote></div><br><br clear=3D"all"><div><br></div>-- <br>= <br>David C. Mountain, Ph.D.<br>Professor of Biomedical Engineering<br><br>= Boston University<br>44 Cummington St.<br>Boston, MA 02215<br><br>Email:=A0= =A0 <a href=3D"mailto:dcm@xxxxxxxx">dcm@xxxxxxxx</a><br> Website: <a href=3D"http://www.bu.edu/hrc/research/laboratories/auditory-bi= ophysics/">http://www.bu.edu/hrc/research/laboratories/auditory-biophysics/= </a><br>Phone:=A0=A0 (617) 353-4343<br>FAX:=A0 =A0=A0 (617) 353-6766<br>Off= ice:=A0 ERB 413<br> --001a11c2a0f467964e04da978822--