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

• cochlea

• 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

• middle ear

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

• Frequency

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

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

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

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

• conduction hearing loss

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

• ringing ears

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

• sensorineural hearing loss

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

• hair cells

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

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

• frequency theory

• 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

• sound shadow

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

• place theory

• provides a barrier that reduces the sound's intensity

• echo location

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

• cochlear implant

• 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