Sound Waves

• Loudness: intensity or strength of a sound. Relates to the amplitude or energy of a wave.
• Pitch: how high or low a sound is, related to frequency
• Quality: sound used to tell the difference between sounds with same fundamental frequencies, but different overtones.
• Sound waves are longitudinal.
• Sound waves can be thought of as pressure waves.
• Sonic: frequencies between 20 Hz and 20000 Hz
• Sounds waves travel through a medium to the ear, where they resonate the eardrum.
• Infrasonic: frequencies less than 20 Hz
• Ultrasonic: frequencies greater than 20000 Hz.
• Speed of sound is medium dependent.
• The speed of sound in air increases as temperature increases.
• When compression meets compression= normal sound intensity
• When rarefaction meets compression= minimal sound intensity
• Fluctuations in sound create beats.
• Acoustics: nature of sound quality.
• Anechoic Chamber: room with sound absorbing materials to reduce echoes.
• Doppler Effect: increase or decrease in pitch of a moving source relative to stationary observer.
• Sonic Boom: created when an object travels beyond speed of sound.
• Sound Barrier: compression of dense air, when object is flying at speed of sound.
• Subsonic: speed of object less than the speed of sound.
• Sonic: speed of object is equal to speed of sound.
• Supersonic: speed of object is greater than the speed of sound.
• Mach Number: ratio of a moving object's speed to the speed of sound in air.