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WAVE and SOUND. Amplitude - is the maximum distance the particles in a wave vibrate from their rest positions. Frequency - the number of waves produced in a given time. Wave Velocity - is the speed with which a wave crest passes by a particular point in space - PowerPoint PPT Presentation
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WAVE and SOUND
Amplitude-
is the maximum distance
the particles in a wave
vibrate from their rest positions.
Frequency - the number of waves produced in a given time
Wave VelocityWave Velocity - is the speed with which a - is the speed 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
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
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
Pitch- description of how high or lowthe sound seems to a person
. Loudness- how loud or soft a sound is perceived to be.
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
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 location of fetus, intrauterine vs ectopic• Check the location of the 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
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.
Infrasound: Paranormal Activity and Religious Activity
• Documentation of infrasound and ghost activity
• Ghosts and spirits emit low frequency 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
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
Doppler EffectChange in the frequency of a sound caused by the motion of either the listener or the source of the sound.
Doppler Effect and Sonic BoomsDoppler Effect and Sonic Booms If the source is moving as fast or faster If the source is moving as fast or faster
than the speed of sound, the sound than the speed of 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.
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
Resonance the frequency of sound waves exactly matches the natural frequency of an object.
Suspension Bridges and Resonance
Bridge Video Clips
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)
How the ear works animation
Cochlear Implants and Hearing Loss
Sound and Fury Debate over Cochlear Implants
Hearing Frequency Test