Do Now Begin copying/drawing this on blank side of paper Coloring can help one distinguish the different parts

Unit 4: Sensation & Perception Hearing

Audition It all begins with sound. Listen to this! (whistle) Sound is mechanical energy typically caused by vibrating objects Vibrations produce movement of air molecules called sound waves

Measuring Sound Measured in decibels Characteristics if sound Frequency – number of complete wavelengths … determine pitch Pitch – the experienced highness or lowness of sound Amplitude (loudness/volume) Complexity (timbre/quality)

Structure of Ear Outer ear Auditory canal Eardrum Middle ear Hammer Anvil Stirrup Oval window Inner ear Cochlea Basilar membrane Auditory nerve Temporal lobe Auditory cortex

Processing Sound how hearing works

Auditory Theories Place Theory Frequency Theory Volley Theory 2018-2019 HSS Economics Quarter 1 Auditory Theories Place Theory differences in pitch result from stimulation of different areas of the basilar membrane (in the cochlea) Frequency Theory AKA – Temporal Theory differences in pitch are due to rate of neural impulses traveling up the auditory nerve Volley Theory surmises that the neurons fire in sequence as a rhythmic volley at higher frequencies. Like going back and forth Allows us to hear things about 1000 waves (the upper 1/3 of a piano) because its combining frequencies Theories of Hearing Which best explains why we hear?

Noise Pollution Lengthy exposure of 90 db causes permanent damage 110 db for 30 minutes causes permanent damage 120 db for 5 minutes causes permanent damage

Deafness Possible Causes Conductive deafness Perceptive deafness Tumor, skull injury, birth defect, poison, rubella Conductive deafness Lack of conduction the to basilar membrane (cochlea) Perceptive deafness Nerve damage

Today Review Begin HW if time HW = Other Senses (Due Mon. 10/22) Sensation & perception Structure of eye Structure of ear Begin HW if time HW = Other Senses (Due Mon. 10/22)