PSY345H5 Lecture Notes - Lecture 6: Helen Keller, Audiogram, Sound
Document Summary
In the 1700s, deafness was proclaimed one of the biggest calamity. She declared that deafness was much more worse than being blind. Deafness was considered so catastrophic that few things were done to help deaf people. However, the first attempts to help deaf people were seen in the early 1800s. The ear converts that physical energy into neuro-impulses that are sent to the brain. Sound is made up of waves of air pressure. A sound wave is one representation of what these waves look like. As we start producing sound, the wavelength moves from resting position to compression to resting position to rarefaction and the cycle continues. Each sound production system involves displacement of sound. However, what material we use will alter what kind of sound wave is produced. Loudness is called amplitude and it is measured in decibels (how loud the sound is). Pitch is called frequency and it is measured in hertz (how high the sound is).
