What is sound?
A: In physics, sound is a vibration that propagates as an acoustic wave, through a transmission medium such as a gas, liquid or solid.
In human physiology and psychology, sound is what?
A: The reception of such waves and their perception by the brain.
Only acoustic waves that have frequencies lying between
about 20 Hz and 20 kHz, the audio frequency range, elicit what?
A: An auditory percept in humans.
In air at atmospheric pressure, these represent sound
waves with what wavelengths?
A: Wavelengths of 17 meters (56 ft) to 1.7 centimeters (0.67 in).
Sound waves above 20 kHz are known as what?
A: Ultrasound and are not audible to humans.
Sound waves below 20 Hz are known as what?
Different animal species have varying what?
A: Hearing ranges.
Acoustics is the interdisciplinary science that deals
with the study of what?
A: Mechanical waves in gasses, liquids, and solids including vibration, sound, ultrasound, and infrasound.
A scientist who works in the field of acoustics is a
A: An acoustician.
Someone working in the field of acoustical engineering
may be called what?
A: An acoustical engineer.
An audio engineer, on the other hand, is concerned with
A: The recording, manipulation, mixing, and reproduction of sound.
Sound can be viewed as a wave motion in what?
A: Air or other elastic media.
Sound can propagate through a medium such as air, water
and solids as what?
A: Longitudinal waves and also as a transverse wave in solids.
Sound waves are generated by a sound source, such as
the vibrating diaphragm of what?
A: A stereo speaker.
The sound source creates vibrations in what?
A: The surrounding medium.
As the source continues to vibrate the medium, the
vibrations propagate away from the source at what speed?
A: The speed of sound, thus forming the sound wave.
The particles of the medium do not travel with what?
A: The sound wave.
This is intuitively obvious for a solid, and the same
is true for what?
A: Liquids and gases.
During propagation, waves can be reflected, refracted,
A: Attenuated by the medium.
If the medium is moving, this movement may increase or
decrease the absolute speed of the sound wave depending on what?
A: The direction of the movement.
For example, sound moving through wind will have its
speed of propagation increased by the speed of the wind if what?
A: If the sound and wind are moving in the same direction.
If the sound and wind are moving in opposite
directions, the speed of the sound wave will be what?
A: Decreased by the speed of the wind.
Medium viscosity determines the rate at which sound is
For many media, such as air or water, attenuation due
to viscosity is what?
Sound cannot travel through what?
A: A vacuum.
The speed of sound depends on what?
A: The medium the waves pass through.
The first significant effort towards measurement of the
speed of sound was made by whom?
A: Isaac Newton.