|Not wishing to be pedantic, but I doubt very much whether any mobile phone transducer would have a useable frequency range extending to 16 kHz. But then again, 8 kHz would work just as well for presbyacustic adults...|
And as far as I recall, significant adaption in hearing is relatively rare, so much so that it used to be one of the diagnostic signs of retrocochlear (e.g. acoustic neuroma) pathology.
On 5 Feb 2009, at 17:16, Eric Jacobs wrote: