Question

Explain how sound waves are processed in the ear and then relayed to and processed in the brain.

Answer 1

Sound waves are detected by the pinna and channeled down the external auditory canal to the eardrum. A chain of bones called the ossicles (made of the malleus, the incus, and the stapes) amplify the vibrations from the eardrum and transmit them to the cochlea, which is a spiral, fluid-filled tube that contains auditory receptors called hair cells. The hair cells transduce the sound vibrations, and the auditory nerve carries these neural signals to the thalamus for initial processing. Then the neural signals are relayed to the auditory cortex, which is located in the temporal lobe. In the auditory cortex, adjacent neurons, or neurons that are closer together, tend to respond to certain frequencies. Other neurons combine the information from these specialist cells to help one recognize and distinguish sounds.

Answer 2

The process of hearing starts by pressure/sound waves that are captured by our ears and taken inside the ear by the ear canal reaching firstly the eardrum. The eardrum then vibrates according to the pressure waves that were captured making the acicular (a set of 3 little bones) enter into motion. These vibrations then move from the acicular to the inner ear. Within the inner ear, we can find the cochlea which is where these mechanical waves are converted into electrical signals and then passed to the brain. The auditory cortex of the brain then interprets this signals as sounds and gives them meaning.