Re: TTS as surrogate for noise exposure measurement

[Andreas Widmann <widmann@xxxxxxxxxxxxxx>]

Hi David,

> Since the original question was really about sound levels at the ear drum while wearing headphones,
Sorry, no, to my understanding one approach of the original question was to define a "standard loudness" by a particular sound:

>> One problem is that I can't think of any household sounds 
>> with a standard loudness.


> 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..
That sounds like a very interesting idea, indeed. I would be definitely interested in such a design!

Best,
Andreas

> On Tue, Apr 16, 2013 at 4:01 AM, Andreas Widmann <widmann@xxxxxxxxxxxxxx> 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@xxxxxxxxxxx>:
> 
> > 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@xxxxxx
> Website: http://www.bu.edu/hrc/research/laboratories/auditory-biophysics/
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