vocab Flashcards
acoustics
branch of physics; the study of physical properties of sound and how sound is generated and propogated
psychoacoustics
study of how humans respond to sound as a physical phenomenon; it is a branch of both psychology and acoustics
sound
physically: result of vibration or disturbance in the molecules of a medium;
psychologically: vibration or distrurbance in the air that is potentially audible, although instruments can measure inaudible sound
sound waves
movements of particles in a medium containing expansions and contractions of molecules
compression or condensation
phase of sound in which vibratory movements of an object increase the density of air molecules bc the molecules are compressed or condensed; opposite of rarefaction
rarefaction
the thinning of air molecules when vibrating object returns to equilibrium; opposite of condensation/compression
simple harmonic motion
back and forth movement of particles when the movement is symmetrical and periodic; also known as sine wave
siusoidal wave
wave w/ horizontal and vertical symmetry bc it contains one peak and one valley; contains a single frequency and is the result of simple harmonic motion
aperiodic wave
waves that do not repeat themselves at regular intervals; their vibratory patterns are random and difficult to predict from one time interval to the next
period wave
sound waves that repeat themselves at regular intervals and are predictable
amplitude
magnitude and direction of displacement; in acoustics, it is the strength or magnitude of a sound signal; the greater the amplitude, the louder the sound signal
intensity
quality of sound that creates the sensation of loudness; physically, intensity is the amount of energy transmitted per second over an area of 1 square meter. it is measured in terms of watts per square meter and is also expressed in decibels
bel
logartihmic unit of measure of sound intensity. it is a basic and relative reference measure that helps express the wide range of sound intensities to which the human ear is sensitive by means of a compressed, logarithmic scale
decibel
measure of sound intensity that equals one tenth of a bel
CSG system
metric system of measuring length in centimeters, time in seconds, and mass in grams; it can be contrasted w/ the MKS system.
MKS system
metric system of measuring length in meters, mass in kilograms, and time in seconds
dyne
measure of force in the CSG metric system; 1 dyne is the force required to accelerate a mass of 1 gram from a velocity of 0 cm per second to a velocity of 1 cm per second
density
around of mass per unit volume; serves as a medium for sound and affects sound transmission
displacement
change in position; air molecules are said to be displaces b/c of the vibratory acceleration of an object
oscillation
back and forth movement of air molecules b/c of a vibrating object
force
vector quantity that tends to produce an acceleration of a body in the direction of its application; it is also defined as the produce of mass and acceleration
elasticity
property that makes it possible for matter to recover form and volume when subjected to distortion
velocity
change in position of, for example, air molecules when an object is set into vibration; is measured in terms of distance an object moves per time and direction it takes to move
frequency
one of the two characteristics of vibratory motion; it is the rate of vibratory motion that is measured in terms of the number of cycles per second; Hz. Hertz is the unit of measure of 1 cycle per second
