Comd 5070- Final Exam Prep/169
Questions with Verified Solutions
what is science? [4 features of the scientific method] - -• Empirical - based
on data
• Deterministic- obeys physical laws
• Predictive- If you do then this will happen
• Parsimonious- uses the simplest explanation
as possible
-the scientific method is _______, ________, ________, and ________ - -empirical,
deterministic, predictive, parsimonious
-science is ________: based on data- we collect data and then interpret it; we
have to make sense of the behavior that we're trying to understand - -
empirical
-science is __________: things obey physical laws; not random in terms of
cause and effect, and can draw generalizations from data that we can extend
on to other situations we have not yet experienced - -deterministic
-science is ________: if a given phenomenon occurs, it can influence another
one; represents cause and effect relationships - -predictive
-science is _________: uses the simplest explanation versus making it
unnecessarily convoluted - -parsimonious
-how many semitones in one octave, two octaves, how many Hz in an
octave, etc. - -• 12 semitones in one octave
• 24 semitones in 2 octaves.
• octaves work in doubling; example 500-1000
is 1 octave 2000-4000 is another octave
-there are _______ semitones in 1 octave
-each semitone is a _________ step- each step upward is _______ than the last
(about 5.9%)
-no semitones are physically identical in Hz, but they SOUND equal in step
size, because our human perception of sound is nonlinear - -12, nonlinear,
bigger
-an _________ is the doubling or halving of a frequency
,e.g. if you have a 400 Hz base and you went up an octave, you would reach
_______ Hz, and if you went down an octave you would reach _______ Hz - -
octave, 800, 200
-Sampling rate [how does it relate to playback quality, frequencies saved in
a recording, Nyquist, aliasing - -• Sampling rate is a snapshot. The more
samples the better it is. Sample rate is in Hz so if you have 10 samples per
second it would be 10 Hz recording.
• The higher sampling rate gives better truth. Higher sampling rate requires
bigger files, which has more memory usage more disk space for storage,
more processing time for computations.
• Nyquist is half the sample rate. This means you need to get twice the
sample of a rate you want. For example, if you want a 10 Hz recording you
need to get a sample rate of 20 Hz recording. If you go with a lower quality
sample rate you would have a longer time and if you would go with a higher
quality you will have a shorter time.
• Compact discs/mp3-44.1 kHz which is 22,050 Hz.
-the frequency rate with which numbers are stored to represent the analog
symbol being sampled is called the ________ ____________, specified in Hz
-the #s represent amplitude values - -sampling rate
-the sample rate for compact discs is _________, this means that the sounds
played back from the compact disc can go up to ___________ - -44,100 Hz,
22,050 Hz
-_________ ________ sounds get lost in a recording with a low sampling rate,
and get misrepresented as _______ _________ sounds, AKA ___________ - -high
frequency, low frequency, aliasing
-_______ _________: filtering before digitizing which prevents
i.e. using a low pass filter to prevent the higher frequencies from even
reaching the digitized system so that they won't contaminate the lower
frequency recording by being represented as an alias - -anti-aliasing
-What are the filter types? - -High pass Filter
Low Pass Filter
Band Pass Filter
Band Reject Filter
, -a ______ _______ filter allows high frequencies through and holds back the
lower frequencies - -high pass
-a _______ ________ filter allows low frequencies through and holds back the
higher frequencies - -low pass
-a _______ _________ filter allows a band of frequencies in the middle through,
and holds back both higher and lower frequencies - -band pass
-a _________ ________ filter holds back a band of frequencies in the middle
and allows both higher and lower frequencies through - -band reject
-disordered voice- disordered vocal fold movement- change in ________
disordered articulation- abnormal movement of the articulators- change in
________ - -source, filter
-a ____ ______ ________ is what you see when you have a microphone
recording in front of you. it represents sound directly- that is, how air
pressure changes over time (y-axis amplitude, x-axis time). if you subject it
to a fourier transform, you get a _____ _______ _____ ________ - -time domain
waveform, frequency domain spectrum display
-a _________ __________ is a line spectrum that shows the frequency
components of a sound (y-axis amplitude, x-axis frequency)
-there is no energy between the harmonics - -frequency domain
-Speech spectrogram axes:
x axis is _________
y axis is _________
darkness indicates ___________ - -time, frequency, intensity
-______ ________: single line on a spectrum
______ _______ ________: multiple lines on a spectrum - -sine wave, complex
periodic signals
-the ___________ ___________ on a noise spectrum is a representation of where
the tops of all the individual sine waves appear and can show us the relative
strength of the different frequency components of the noise - -spectral
envelope
-Random cycle to cycle duration differences
Frequency perturbation - -jitter
-Rhythmic change in fundamental frequency and amplitude. - -tremor
-Random cycle to cycle amplitude differences