exam 1 lectures 6 and 7 Flashcards
(31 cards)
small frequency difference between f1 and f2
beating stimulus
modulations arise from ———— between two or more frequency components (sine waves)
INTERFERENCE
(f1 + fz)/2
frequency of the single tone
|f2-f1|
frequency of beats
common lab stimulus to study amplitude modulation
sinusoidally amplitude modulated (SAM) tone
frequency modulated (FM) tones
chirps
(also called tone-sweeps)
how do characterize the frequency content of an FM sound?
long-term specturm
short-term spectrum
spectograms represent three dimensions:
amplitude
frequency
time
a VERY brief pulse is referred to
transient/click
aperiodic signals have continuous…
spectrum
increasing the period of the pulse train —— the fundamental frequency
lowers
the increase in spectral width over which tone energy spreads as duration decreases is called
spectral splatter
the bandwidth of the click is ——— proportional to its duration
INVERSELY
BW = 1 / DURATION
a sound with an instantaneous amplitude that varies over time in a random manner
noise waveform
Guassian Noise
continuous and flat average power spectrum over its bandwith
white noise
roll-off of 3 dB for every doubling (octave) of frequency. noise energy is constant in each OCTAVE
pink noise
variation of a variable with time (conveys information)
ex: time domain in waveform
signal
something that modifies one signal (input) to create another (output)
system
change the amplitude spectrum of a signal by some number of dB for each frequency component
filters
passes low frequencies and attenuates high frequencies
low-pass
passes high frequencies, attenuates low frequencies
high-pass
passes a range of frequencies and attenuates the rest
band-pass
attenuates a range of frequencies and passes the rest
band-stop
factor by which the input is multiplied
gain
