[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: TTS as surrogate for noise exposure measurement

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@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.

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/
Phone:   (617) 353-4343
FAX:     (617) 353-6766
Office:  ERB 413