Mods 20 & 21 Reading Guide

Air molecules, each bumping into the next, create _______ of compressed and expanded air, like the ripples on a pond circling out from a tossed stone.

The height, or ​ (a)   of sound waves determines their perceived ​ (b)   . Their length or ​ (c)   determines the ​ (d)   we experience.

• amplitude
• loudness
• frequency
• pitch

We measure sound amplitude in ________, with zero decibels representing the absolute threshold for hearing.

Match the following

• Frequency

• the number of complete wavelengths that pass a point in a given time

• pitch
• a tone's experienced highness or lowness; depends on frequency
• cochlea

• the innermost part of the ear, containing the cochlea, semicircular canals, and vestibular sacs

• middle ear

• a coiled, bony, fluid-filled tube in the inner ear through which sound waves trigger nerve impulses

• inner ear

• the chamber between the eardrum and cochlea containing three tiny bones (hammer, anvil, and stirrup) that concentrate the vibrations of the eardrum on the cochlea's oval window

Which statements are correct

• hair cell movements trigger impulses in adjacent nerve cells

• the auditory nerve carries the neural message to your thalamus

• the thalamus transmits neural messages to the auditory cortex in your brain's temporal lobe

• Sound goes from vibrating air, to tiny moving bones (in your ear), to fluid waves, to electrical impulses to the brain

Match the following

• sensorineural hearing loss

• a sign that we have been listening to noise that is too loud and our hair cells are damaged

• hair cells

• hearing loss caused by damage to the cochlea's receptor cells or to the auditory nerves; also called nerve deafness

• conduction hearing loss

• quivering bundles that let us hear and number close to 16,000 in the ear

• ringing ears

• hearing loss caused by damage to the mechanical system that conducts sound waves to the cochlea

Prolonged exposure above __ decibels produces hearing loss.

Teen boys more than teen girls or adults ​ (a)   themselves with loud volumes for long periods. ​ Males' ​ (b)   noise exposure may help explain why men's hearing tends to be ​ (c)   acute than women's.

• blast
• less
• avoid
• greater
• more
• weaker

Match the following

• cochlear implant

• the use of reflected sound waves to determine distance or to locate objects

• echo location

• in hearing, the theory that the rate of nerve impulses traveling up the auditory nerve matches the frequency of a tone, thus enabling us to sense its pitch

• place theory

• provides a barrier that reduces the sound's intensity

• sound shadow

• the theory that links the pitch we hear with the place where the cochlea's membrane is stimulated

• frequency theory

• a device for converting sounds into electrical signals and stimulating the auditory nerve through electrodes threaded into the cochlea

Sharks and dogs rely on their outstanding sense of ​ (a)   ...Our human brain allocates more real estate to ​ ​ (b)   and ​ (c)   . Without our senses of touch, ​ (d)   , smell and ​ (e)   , we humans would be seriously hampered, and our capacities for enjoying the world would be greatly diminished.

• smell
• seeing
• hearing
• taste
• body position and movement