WEEK 7 discussion

In this week the subject was the auditory system. In the lecture we got introduced to the inner ear parts, which are extremely small and complex in their function and structure. There was nothing completely new that I learned but I got more depth on knowledge about inner ears function (basilar membrane, movement of hair cells and their action potentials). I learned how the organ of Corti works. It consists of basilar membrane in the bottom, tectorial membrane on the top with hair cells (inner and outer) in between. When sound waves travel to the inner ear, it moves the basilar membrane which again causes tension on hair cells’ cilia. This again causes an opening of potassium ion channels which leads to a depolarization and in the end to an action potential. I was surprised to learn that there is the amplifying mechanisms in the ear: outer hair cells can amplify the sound signal by moving the membrane. The amplifying mechanism is also present in other parts of the ear in different form, e.g. eardrum and ossicles.

We also discussed about sound localization and how outer ear is responsible for this mostly. I was wondering how this is affected when the shape of the ear is altered, either while using something that presses the ear (like earmuffs) or in case of damage in the outer ear. How the brain will determine where the sound comes from? Specially if only one of the ears shape is altered.