Limits of the ear and hearing research
In the lecture we learned that our ears have an attenuation reflex for preventing loud sounds from damaging the ear. However, this reflex has a quite substantial delay, so that sudden sounds can pass before the reflex kicks in. We wonder, why is the reflex so slow? Is it perhaps that in the past there wasn’t as many loud sudden sounds that the evolutionary pressure was not great enough? Or is there some biological limitation that prevents faster response?
During the lecture we also saw some tonotopic maps of how / where different sound frequencies are analyzed in the temporal lobe of the brain. The first picture shown in the lecture, which was also in the book, showed a quite horizontal organization for evenly spaced, evenly sized portions for frequencies that double at each boundary. According to the lecturer this is wrong, and we were shown some alternative maps. However, these maps were said to also be slightly incorrect. Why is it, that though we seem to have knowledge on the tonotopic organization, the maps we use are wrong? We wonder, how we could know if the graphics are wrong, if there aren’t any correct graphics to learn from?
It is generally accepted that our ears get worse as we age, as in the range of sound frequencies we can perceive narrows down as we get older. We wonder, how much this is influenced by the industrialized modern world. Did the worsening of hearing occur to the same level before the modern world at all? This could be studied by comparing the effect between people living in cities versus people living in very remote places.
Based on our test with the speakers on a laptop, we still heard this sound. Do you?