COMD 5070- FINAL EXAM PREP QUESTIONS AND
ANSWERS
What is science? [4 features of the scientific method] - answers -• 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 ________ - answers -
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 - answers -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 - answers -deterministic
Science is ________: if a given phenomenon occurs, it can influence another one;
represents cause and effect relationships - answers -predictive
Science is _________: uses the simplest explanation versus making it unnecessarily
convoluted - answers -parsimonious
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 - answers -sampling rate
The sample rate for compact discs is _________, this means that the sounds played
back from the compact disc can go up to ___________ - answers -44,100 hz, 22,050 hz
_________ ________ sounds get lost in a recording with a low sampling rate, and get
misrepresented as _______ _________ sounds, aka ___________ - answers -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 - answers -anti-aliasing
What are the filter types? - answers -high pass filter
,Low pass filter
Band pass filter
Band reject filter
A ______ _______ filter allows high frequencies through and holds back the lower
frequencies - answers -high pass
A _______ ________ filter allows low frequencies through and holds back the higher
frequencies - answers -low pass
A _______ _________ filter allows a band of frequencies in the middle through, and
holds back both higher and lower frequencies - answers -band pass
A _________ ________ filter holds back a band of frequencies in the middle and allows
both higher and lower frequencies through - answers -band reject
Disordered voice- disordered vocal fold movement- change in ________
Disordered articulation- abnormal movement of the articulators- change in ________ -
answers -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 _____
_______ _____ ________ - answers -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 - answers -frequency domain
Speech spectrogram axes:
X axis is _________
Y axis is _________
Darkness indicates ___________ - answers -time, frequency, intensity
______ ________: single line on a spectrum
______ _______ ________: multiple lines on a spectrum - answers -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 - answers -spectral envelope
Random cycle to cycle duration differences
Frequency perturbation - answers -jitter
, Rhythmic change in fundamental frequency and amplitude. - answers -tremor
Random cycle to cycle amplitude differences
Amplitude perturbation - answers -shimmer
Much slower than random cycle to cycle perturbation - answers -modulation
How many semitones in one octave, two octaves, how many hz in an octave, etc. -
answers -• 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 - answers -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 - answers -octave,
800, 200
Sampling rate [how does it relate to playback quality, frequencies saved in a recording,
nyquist, aliasing - answers -• 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.
What does noise look like on a spectrum? (3) - answers -all frequencies, equal
amplitudes, random phase
A ______ _______ ________ spectrum display clearly shows harmonic energy that is
present in a complex sound