This week’s topic was again very interesting, and I again came up with a few questions. In the stimulus intensity part, it was mentioned that when a stimulus gets more intense, more hair cells are activated, and that the increase in the number of activated hair cells causes a broadening of the frequency range to which the fiber responds. Does this mean, that it is more difficult to realize the frequency of noise when it’s louder?
Also it was mentioned that the hearing frequency range (20-20,000 Hz) decreases with age, especially at the high-frequency end. But it was never explained why this happens. Do the hair cells or the stereoclia get damaged with age, or do they wear out?
Finally a third question, how linear is the tonotopic map on the basilar membrane, and is there much variability between people? For example, some people have better “sävelkorva” than others, could this have something to do with the properties of of the basilar membrane? Could it be possible that because of small irregularities in the basilar membrane, some frequency ranges are heard better than others? Or that some people are just unable to recognize some frequencies properly, because hair cells with that characteristic frequency just doesn’t exist?