PSY 217 Lecture 7: Noise (Week 9)

• School: Ryerson University
• Department: Psychology
• Course: PSY 217
• Professor: Paolo Ammirante

Document Summary

Sound waves are successive pressure disturbances in some way (air) Able to graph changes in air pressure. Amplitude - height of peaks, measured in decibels (db) Frequency - difference between peaks, measured in hertz (hz) or number of cycles per second. Pinna (outer ear) - collects and directs sound waves to middle ear. Middle ear - vibration of the eardrum amplified by three tiny bones. Innear ear - vibrations converted to neural impulse in the cochlea. Cochlea - fluid filled coil in inner ear that contains receptors for hearing. Basilar membrane - runs length of cochlea has tiny hairs protruding from it. Vibrations from middle ear bones creates wave of fluid traveling along cochlea. Fluid waves stimulate hair cells as they pass. Stimulation converted to neural impulses that are sent to brain. Place theory - perception of pitch corresponds to place of vibration along basilar membrane. High pitches located in opening of cochlea, low pitches located in the end.