All Sounds Are Produced by Something That ______

Chapter 21 Sound

Section 21.1

What is Sound

•All sounds are produced by something that ______

•A wave carries energy from one place to another and without transferring ______

•The vibrating object causes air molecules to ______back and forth

•As these air molecules ______with those nearby , they cause other molecules to move back and forth

•A sound wave is a ______wave, like a wave moving through a coiled spring

•In sound waves, ______move back and forth along the direction of the wave

Making Sound Waves

•When an object ______, it exerts a force on the surrounding air

•For example, as the end of the tuning fork moves outward into the air, it ______the air molecules together

•As a result, a region where the air molecules are closer together, or more ______, is created

•This region of high density is called a ______

•When the tuning fork moves back it causes an area of low density called ______

•The compression and rarefaction ______from the tuning fork as molecules collide with one another

•Sound waves can be described by its ______and frequency

•Wavelength is the distance between two consecutive ______or two consecutive rarefaction

•______of a sound is the number of compressions or rarefactions that pass by a given point in one second

Speed of Sound

•Speed of sound varies because of ______and material it is passing through

–Sound moves faster in ______then liquids or gases because the particles that makes solid up are closer together

–Sound is slowest in ______because molecules are farther apart

–As the temperature heats up its molecules move ______, so they collide more frequently

•More frequent the collision the faster sound ______

•0* C sound travels a ______, 20*C 343m/s

Amplitude and Loudness

•Loudness is the human ______of how much energy a sound wave is carrying

•The amount of energy a wave carries depends on its ______

–Higher amplitude- more ______the particles in a compression are and the farther they are spread out in a rarefaction

– Higher amplitude means more ______and louder

Decibel Scale

•Scale used to describe sound ______

•Increase in 10 decibels means that the energy carried by the wave has increased ____ times

•Increase in 20 decibels, energy increases ______times

•Increase in 30 decibels, energy increased ______x

•Hearing Damage begins to occur at 85 dB

•Jet Plane = ______dB

•Whisper =______dB

•Lawn Mower =______

Frequency and Pitch

•______of a sound is how high or low it sounds

•Pitch corresponds with ______of the sound

•Higher the pitch the ______the frequency

•Lower the pitch the ______the frequency

•Human ear can detect sound waves with frequencies between about ____Hz and ______Hz.

•Dogs can hear frequencies up to almost ______Hz

•Dolphins and Bats can hear frequencies as high as ______Hz.

•Higher pitch - shorter ______, Lower pitch – Longer ______

•Length and thickness of your ______help determine your pitch

•Short thinner vocal cords vibrate at higher frequencies, results in ______voices

•______in throat can stretch the vocal cords tighter, letting people vary their pitch

Echoes

•A echoes is a ______sound wave

•Sound waves reflect off of ______surfaces

•______systems use sound waves to map out objects underwater

–The amount of time it takes for ______to return depends on how far away the reflecting surface is

•______– the ability to emit high pitched squeaks and listen for echoes. Used to navigate and hunt

•______and ______use echolocation

Doppler Effect

•The change in a frequency that occurs when the source of the sound is moving relative to a ______is the Doppler effect

•Occurs whether the ______or the listener is moving

•As you move closer to the source you encounter each sound wave a little ______

–The closer you get the higher the ______

•When you move away , each sound wave takes ______to reach you, you hear fewer wavelength, which results in a lower pitch

•______used to determine speed of cars and baseballs use the Doppler Effect

Diffraction

•Diffraction means that sound waves can ______around obstacles or spread out after passing through a narrow opening

•The amount of diffraction depends on the ______

•If Wavelength is much ______than the obstacle, almost diffraction occurs

•If wavelength is ______or larger then the size of the obstacle, the amount of diffraction increases

Using Sound Waves

•______– using high frequency sound waves as an alternative to some surgeries

–______and gall stone sometimes can be broken up using ultrasound

–Used to exam a developing ______, and internal organs

The Ear

•The ear is a complex organ that is able to detect a wide range of ______

•Has three parts

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–

–

•The Outer Ear

–Collects ______and directs them into the ear canal

–Shaped like a ______to collect sound waves

–Animals that rely on hearing to locate predators or pry often have ______and can be adjusted

•Rabbits and Owls

•The Middle Ear

–Sound waves vibrate the ______

–Eardrum is a Thin ______that stretches across the ear canal

–As the eardrum vibrates, it transmits vibrations to three small ______

–

–

–

•The bones ______(intensify) the vibrations

•Similar to how a ______can change a small movement at one end into a large movement at the other end

•Inner Ear

–The stirrup vibrates a second membrane called the ______

–Inner ear is filled with______

–Vibrations are transferred to ______tipped cells in the cochlea

–Different ______vibrate the hairs differently

–Cells generate signals containing information about the ______y, intensity, and ______of the sound

•The nerve impulse travels to the brain along the ______nerve

Hearing Loss

•The ear can be damaged by ______, age, and ______to loud sounds

•Constant exposure to loud sounds can damage the ______in the cochlea

•If hair cells die, hearing loss occurs because mammals can not ______new hair cells

•Higher______hearing is usually the first to be lost

•Soft consonants sounds such as ______are hard to hear

•People with high frequency hearing loss have trouble distinguishing these sound during ______

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