WAVE and SOUND

Amplitude-

is the maximum distance

the particles in a wave

vibrate from their rest positions.

Frequency - the number of wavesproduced in a given time

Sound Terminology

Wave VelocityWave Velocity - is the - is the speedspeed with which a with which a wave crest passes by a particular point in wave crest passes by a particular point in spacespace

It is measured in meters/second.It is measured in meters/second.

Wave VelocityWave Velocity = = Frequency Frequency Wavelength Wavelength

Sound Terminology

Speed of Sound• Medium velocity m/sec

air (20 C) 343

air (0 C) 331

water (25 C) 1493

sea water 1533

diamond 12000

iron 5130

copper 3560

glass 5640

Pitch- description of how high or lowthe sound seems to a person Higher Pitch means Increased Wave Frequency

Tone: A sound of distinct pitch, quality, and duration; a note.

. Loudness- how loud or soft a sound is perceived to be.

Sound Terminology

CLICK HERE: Loudest Speakers

Analysis Question: What is the relationship

between PITCH AND WAVELENTH?

Sound Terminology

• Acoustics: the study of all mechanical waves in gases, liquids, and solids including vibration, sound, ultrasound and infrasound.

• Decibel: ( dB) is used to measure sound level, but it is also widely used in electronics, signals and communication.

Loudness of Sound in DecibelsSound Loudness (dbs) Hearing

Damage

Average Home 40-50

Loud Music 90-100 After long exposure

Rock Concert 115-120 Progressive

Jet Engine 120-170 Pain

Are Sound vibrations visible???

• http://www.kirotv.com/videos/news/video-what-does-washingtons-loudest-car-stereo/vCM4g4/

Think, Pair and ShareComplete the following Hypothesis:

If you are exposed to sounds louder than 200 decibels, then your internal organs most likely will _____________________________________________ because __________________________________________________.

Sounds and Mediums

• Waves must have medium in order for sound to be heard– Of the three mediums (gas, liquid, and solid)

sound waves travel the slowest through gases, faster through liquids, and fastest through solids.

– Temperature affects the speed of sound. • http://www.ndt-ed.org/EducationResources/HighSc

hool/Sound/tempandspeed.htm

Ultrasound

- sound waves with frequencies above the normal human range of hearing Sounds in the range from 20-100kHz

Infrasound - sounds with frequencies below the normal human range of hearing.Sounds in the 20-200 Hz range

Obstetric Ultrasound

• Date the pregnancy (gestational age)• Confirm fetal viability (if it is living)• Determine placement of fetus, intrauterine vs ectopic• Check the location of placenta in relation to the cervix• Check for the number of fetuses (multiple pregnancy)• Check for major physical abnormalities• Assess fetal growth• Check for fetal movement and heartbeat.• Determine the sex of the baby

http://www.chloetufts.com/ultrasound/index.php

4 D Ultrasound Images

Animals In Utero

Other Uses of Ultrasound • Medical

– Detecting blood-clots in arteries and veins– Eye scans – Any soft tissue scans (organs, skin, muscles, etc)– Biopsies– Break up kidney stones – Chemotherapy - delivery of medicines using high frequency

• Jewelry Cleaning - UltraSonic • Humidifiers• Identification Badges• Sonar - in submarines and ships • Product testing – finds flaws in materials• Used in Horses to detect injuries• Used in Beef Industry to evaluate fat thickness, rib-eye

area and to improve breeding procedures

Ultrasound in Animals

• Echolocation (Echoes) - Sonar– Using echoes for communication, navigation

and foraging – Bats and Whales / Dolphin, Shrews, Cave-

dwelling birds, Tenrecs – Humans use of echolocation

• Called “Perceptual Mobility”• Blind persons

•Whales, elephants, hippopotamuses, rhinoceros, giraffes, Okapi and alligators are known to use infrasound to communicate over distances—up to hundreds of miles in the case of whales. •Tigers use low frequency growls to

paralyze their prey

•It has also been suggested that migrating birds use naturally generated infrasound, from sources such as turbulent airflow over mountain ranges, as a navigational aid.

ANSWER THE FOLLOWING:

TRUE OR FALSE: SIGHT IS THE PRIMARY SENSE FOR ALL ANIMALS

COMPLETE THE FOLLOWING STATEMENT:

SOME ANIMALS NEED INFRASOUND AND ULTRASOUND BECAUSE __________________________________________________________________________________________________

HUMANS NORMALLY DON’T NEED INFRASOUND OR ULTRASOUND BECAUSE ____________________________

EXPLAIN THE EVOLUTIONARY ADAVANTAGES OF INFRASOUND AND ULTRASOUND.

Infrasound: Paranormal Activity and Religious Activity

• Documentation of infrasound and ghost activity

• Ghosts and spirits emit lowFrequency sound waves

• Extreme bass of Organ music triggers spiritual feelings or a feeling of a person nearby or a presence.

Infrasound and Other Mental and Physical Effects

• Infrasound can cause fear, have a negative effect on a person physically and even cause death. – Elevated blood pressure and heart rate,

nausea– Release Endorphins leads to adrenaline

response – Anxiety, coldness, tingling sensations,

sorrow, shivers down the spine

WARM UP 3/12 WEDNESDAY

Describe a situation where CONSTRUCTIVE INTERFERENCE would be necessary or beneficial.

Describe a situation where DESTRUCTIVE INTERFERENCE would be necessary or beneficial.

Interference• The result of two or more sound

• Waves Overlapping

Interference

Constructive Examples

• Iridescence – Bubbles – Butterfly wing colors

• Musical Instruments – Instruments harmonize

and become one sound

Destructive Examples

• Noise Cancelling Headphones– Pilots – decreases noise

from high decibel environments

– Construction Workers

You are standing by the side of the road. A car horn blares as it comes toward you and passes you at constant speed. The PITCH of the horn that you hear

a.gets higher and higher as the source approaches and gets lower and lower as the source recedes

b. stays at a constant high pitch as the source approaches and then drops to a constant lower pitch as the source recedes

c. stays at the same constant pitch throughout the motion

d. maintains the same pitch except at the moment the source passes

e. varies too much to tell what the pitch is doing

DRAW A DIAGRAM TO EXPLAIN YOUR ANSWER

PITCH AND THE DOPPLER EFFECT

Doppler EffectChange in the frequency of a sound caused by the motion of either the listener or the source of the sound.

Sonic BoomsSonic Booms If the source is moving as fast or faster If the source is moving as fast or faster

than the than the Speed of sound Speed of sound the sound the sound waves pile up into a shock wave called waves pile up into a shock wave called a a sonic boom.sonic boom.

Enormous energyEnormous energy A sonic boom sounds very much like A sonic boom sounds very much like

the pressure wave from an explosionthe pressure wave from an explosion The crack of a bull-whip is a The crack of a bull-whip is a smallsmall

sonic boom. sonic boom.

Sonic booms are usually associated with Space Shuttle Landings or large aircraft.

Resonance the frequency of sound waves exactly matches the natural frequency of an object. A Forced Vibration.

An example of resonance: A motor that causes vibration in a piece of furniture in another part of the same house. These vibrations occur because the furniture has a natural frequency equal to the frequency of the vibrations set up by the motor. 

Bridge Video Clips

Mythbusters Resonance

Mechanical Resonance can produce vibrations strong enough to destroy the object in which they occur. • For example, soldiers marching over a bridge can cause extreme vibrations at the bridge's natural frequency and shake it apart. For this reason, soldiers break step to cross a bridge.• In 1940 wind gusts at Puget Sound Narrows, Tacoma, Washington, caused a suspension bridge to vibrate at its natural frequency and the bridge collapsed.

In Music, resonance is used to increase the intensity (loudness) of a sound. The comparatively weak vibrations produced at the end of an organ pipe, for example, cause a column of air in the pipe to vibrate in resonance, thus greatly increasing the loud-ness of the sound.

In humans, the vibrations of the vocal cords are reinforced by resonant vibrations in the oral and nasal passages.

Steven Tyler Vocal Chords

Video of Vocal Chords

Can the human voice shatter glass????

• Everything has a Resonant Frequency• the speed at which it will vibrate if bumped or otherwise

disturbed by some stimulus, such as a sound wave• Glass wine goblets are especially resonant because of their

hollow tubular shape • If a person sings the same tone as that ringing note, the

sound of the voice will vibrate the air molecules around the glass at its resonant frequency, causing the glass to start vibrating as well.

• If sung loudly enough, the glass will vibrate itself to smithereens.

Mythbusters Rock Star SingingKid Breaking Glass

Resonance and the Singing Glass

Resonance

• Adding energy into the substance at its resonant frequency will force it to vibrate or resonate

• As your finger slides and sticks along the surface of the rim, energy is added to the glass molecules and causes them to resonate.

• The motion of your hand sets up a wave of vibration traveling through the glass.

• The vibrations cause air molecules to vibrate at the same frequency.

• The vibrating air molecules are the sound wave that you hear

Glass Singing

Electrical Resonance

Electrical resonance• is used to tune radios

and television sets. • Tuning consists of

establishing a circuit with a resonant frequency equal to the assigned frequency of the desired station.

Magnetic Resonance ImagingMRI

• Medical imaging using powerful magnets, radio frequency and atoms in the body – Used for more detailed images of the heart,

brain, etc. Used to detect cancers– No Ionizing radiation (cancer causing)

Colors of Noise • Different audio signals

– used in engineering, electronics and physics

• Each sounds different to the human ear

• Each has a different spectral reading – White– Pink– Red (Brown)– Gray– Blue – Violet– Black – Green

White Noise

• White noise does not vibrate at one specific frequency

• It covers a range of frequencies.

• Often used as sirens by the emergency services

• It cuts through background noise and does not echo so it is easier to perceive the direction the vehicle is travelling.

White Noise Sound MachinesLink: White Noise Sound Machines Used to help Babies sleep

may be doing harm

STRUCTURE FUNCTION

PINNA Outer part of the external ear. It amplifies sound by funneling it from a large area into the narrower auditory canal.

AUDITORY CANAL Carries sound waves to the tympanic membrane.

OSSICLESHammer: Malleus Anvil: Incas Stirrup: Stapes

Tiny bones that amplify and carry sound in the middle ear.

TYMPANIC MEMBRANE (EAR DRUM)

Receives sound waves.

EUSTACHIAN TUBE Air-filled tube of the middle ear that equalizes pressure between the outer and middle ear.

VESTIBULAR NERVE Chamber at the base of the semicircular canals. Also associated with equilibrium.

SEMI-CIRCULAR CANALS Fluid-filled structures that provide information concerning equilibrium.

COCHLEA Coiled tube within the inner ear that receives sound waves and converts them into nerve impulses.

HEARING LOSS TYPES• CONDUCTIVE

– Sound doesn’t move correctly through the ear drum, ear canal or ossicles

– Sounds like ears are plugged

– Person may speak softly b/c their voice seems loud to them

– Causes

• Earwax

• Punctured eardrum

• Fluid in the ear

• Genetic defect

• Infection

– Treatment

• Surgery

• Medicine

• Hearing Aid

• Cochlear Implant

• SENSORINEURAL• Damage to the Cochlea or Nerves

• 90% of people with hearing loss

• Gets worse over time

• Some can hear, but can’t understand what people are saying

– Causes

• Aging

• Infections

• Head Trauma

• Genetics

• Exposure to loud noises

• Fluid build-up

-Treatment: Usually can’t be treated

• Depends on the Specific Damage

• Hearing Aid

• Cochlear Implant

Perforated Eardrum

Otoscope: Instrument used to view the ear drum Never use Q-tips!!

Ear Tubes Decrease Pressure in the Ear

Drainage is normal after surgery

Hearing Aids • Electronic Devices that amplify sounds• Hair cells in the ear detect vibrations and convert to

nerve signals • Not effective for everyone • Only 1 in 5 people use due to embarrassment or financial

reasons• Consists of

• a microphone• amplifier • receiver/ speaker • battery

• Over 28 million people suffer from hearing loss

COCHLEAR IMPLANTS

Cochlear implants bypass damaged portions of the ear and directly stimulate the auditory nerve.

Cochlear Implants and Hearing Loss

Hearing Frequency Test: EXTRA CREDIT!!!!

Cochlear Implant: Girl Hears for the First Time

Julianna Wetmore: Treacher Collins Syndrome

VIDEOS AND ANIMATIONS

INTERESTING FACT!! The more intense a sound is, the louder it will be. Normal sounds carry small amounts of energy, but HUMAN ears are very sensitive

IF we had enormous ears like Dumbo’s, we could hear a sound delivering to this area an energy of only one Trillionth of a joule each second!

Since our ears are thousands of times smaller, the energy our ears receive in a second is thousands of times less.