
Originally Posted by
Themis
The "limit of human discernment" is frequency-independent ?
It is frequency dependent and different for each individual.
Those fitted with digital hearing aids (like me) go through a testing procedure conducted by an audiologist.
How these factors affect the current discussion, I don't know.
In my primitive understanding there are three factors:
The threshold of hearing.
The threshold of pain.
The ability to discern differences in sound intensity between the two above limits.
All, I believe, vary with frequency and between individuals.
The digital hearing aid is adjusted in a number of frequency bands to optimise the energy injected into the ear without crossing the threshold of pain at any frequency. This I did not appreciate till the fitting. For years in the Army my ears were tested - the threshold of hearing at all frequencies. When the aid was fitted a second test was done to establish the maximum volume I could tolerate at any frequency. Fascinating subject, and I with I understood more.
For those with impaired hearing the difference between the threshold of pain and the threshold of hearing is reduced; which is why, perversely, the deaf cannot tolerate loud noise, and especially high frequency noise. Those with good hearing cannot understand this.
Last edited by Labarum; 10-10-2009 at 12:46.
Brian
In Southampton: Raspberry Pi 4 running PiCorePlayer, Beresford Caiman SEG, Quad 77 Int Amp and CD Player, AVI Neutron 4, Sennheiser HD25 headphones.
In Nicosia: Small Format HTPC, Beresford 7520 ,Quad 405-2, Quart 980s German Tower Loudspeakers.