Ch 1 - Flashcards
what is frequency measured/ expressed in?
hertz (Hz)
1 Hz = 1 cycle per second
what influences frequency?
mass
length
stiffness
what influences intensity?
force
pressure
power
what is intensity measured/ expressed in?
decibel (dB)
1 dB = 1/10 Bel
who is Hz named after?
Heinrich Hertz
who is the Decibel named after?
Alexander G. Bell
resonance
the continuation of sound due to reflection.
resonant frequency
sound pressure
the deviations in the pressure (deviations from atmospheric pressure) caused by a sound wave.
Explain sine waves
- a sine wave/ sinusoid represents a single pure tone
- different aspects of the sine wave are used to represent different properties of the sound.
what is displacement?
occurs when a object is moved from one point to another point.
(ex. tuning fork)
what is the order of a sine wave?
resting
outward displacement
resting
inward displacement
repeat!
what is a cycle?
movement away from one point and return movement to the same point in the same direction.
what is a period?
the same time required for the completion of the complete cycle of movement.
what is the frequency determined by in sine waves?
- the number of cycles of the sound occurring in 1 second (time)
- the distance from the initial point on a sine wave to a second point 360 degrees after the initial point (distance)
what is a phase?
the phase of a sine wave is the point at which the wave begins.
what is considered the starting phase for a sine waves?
o degrees
waves that start in the same point are what?
in phase
waveforms with different starting points are what?
out of phase
an opposite phase is used to describe what?
180 degrees out of phase
what is damping?
- decreased vibration due to resistance.
- the amplitude in a waveform decay or fade away overtime.
- begins almost immediately, and the amplitude of the displacement gradually decreases
what is a pure tone?
a sound with a waveform that exhibits sinusoidal wave motion and consists of only one frequency.
what is a sound complex or a complex sound?
a soundith a non- sinusoidal waveform and consists of multiple frequencies.
how is sound level measured and quantified?
with a sound level meter
what does a sound level meter consist of/ do?
- microphone
- detects sound
- converts acoustic energy to an electrical signal then its quantified in decibels
- a meter
- a needle or a digital display, representing the measured sound level.
why is intensity calibration important?
for accurate hearing research and hearing results