Although conventional hearing aids, which are basically just electronic amplifiers, help their users hear quiet sounds, they are in many cases worse than useless in situations where there is lot of competing sounds, such as in a crowded room with many people speaking at once. In these situations, the competing sound is amplified just as much as the sound of interest and no advantage is obtained from the aid. Researchers such as Brian Moore at the University of Cambridge are using their measurements of the limitations associated with hearing impairment in order to design the next generation of hearing aids. Without a thorough knowledge of the psychoacoustics of hearing impairment such design would be by trial and error. With the appropriate information, however, it is possible to design an aid that can compensate directly for the individual's specific disability.
Human beings are naturally very curious creatures.
We like to know why things are the way they are. Sounds are so important to us in so many different areas that one might expect a great deal of interest in why we perceive sounds in the way that we do. To be honest, however, many psychology students run screaming from lectures in hearing. I believe this is more to do with the frequently technical nature of the subject matter than a lack of desire to learn about hearing. This is a shame because the basic findings of psychoacoustics can be understood without a detailed background knowledge.