COMD 5070 Exam WITH LEGIT QUESTIONS
AND WELL VERIFIED
ANSWERS(NEW!!!)(NEW!!!)
What is science? (4 features of the scientific method) - ANSWER>>>1. Empirical
2. Deterministic
3. Predictive
4. Parsimonious
Empirical - ANSWER>>>based on data
Deterministic - ANSWER>>>Obeys the laws of physics
Predictive - ANSWER>>>cause-and-effect relationships
Parsimonious - ANSWER>>>use the simplest explanation possible
semitone - ANSWER>>>smallest distance between two pitches (half step)
How many semitones are in one octave? - ANSWER>>>12
How many semitones are in two octaves? - ANSWER>>>24
If you want to go up one octave, you ______ the frequency. But if you want to
go down an octave, you _____ the frequency. - ANSWER>>>Double, halve
how many hertz is in an octave? - ANSWER>>>There's no fixed number of hertz
between octaves
,sampling rate - ANSWER>>>frequency with which numbers are stored or written
down to represent the analog signal that you're sampling
- measured in Hz (how many samples stored in one second)
Nyquist frequency - ANSWER>>>half the sample rate
represents the highest frequency that your recording can accurately reproduce
when you play it back
ex. if you want to go up to 10 kHz, you have to double that number to choose a
sample frequency
sampling theorem - ANSWER>>>gives the minimum sampling rate which allows
the original signal to be reconstructed perfectly
aliasing - ANSWER>>>one sound is misrepresented as another
another concept to think about when choosing a sample rate
if you record a signal at a too-slow sample rate, there will be things happening
in the original signal that occur between the samples or snapshots you take
(inaccurately records the original signal)
filtering before digitizing prevents this (using a low-pass filter for anti-aliasing)
Example sampling: If the data is 5 kHz, you should sample at ______ kHz. -
ANSWER>>>10
How does sampling rate relate to playback quality? - ANSWER>>>The more
samples you take, the better chance you have of representing the original
signal.
what does a filter do? - ANSWER>>>removes certain things you don't want
allow you to be selective in what frequencies come through
filter types - ANSWER>>>high pass
low pass
band pass
, band reject
high pass filter - ANSWER>>>Only allows high frequencies to pass through.
low pass filter - ANSWER>>>Only allows low frequencies to pass through. blocks
high frequencies
band reject filter - ANSWER>>>Rejects or attenuates a band of frequencies, but
allows high and low frequencies to pass through.
band pass filter - ANSWER>>>a specified range of frequencies between the low-
and high-pass cutoff frequencies to be passed effectively.
time domain display - ANSWER>>>x-axis: time
y-axis: amplitude
waveform
represents sound directly
air pressure changes over time
frequency domain display - ANSWER>>>x-axis: frequency
y-axis: power or amplitude
spectrum
shows individual harmonic components
also shows the relative proportions of each component
- peaks represent the individual harmonic components represented in this voice
signal
types of spectra - ANSWER>>>line spectrum
FFT (Fast Fourier Transform)
LPC (Linear Predictive Coding)
line spectrum - ANSWER>>>shows the frequency components of a periodic
sound
AND WELL VERIFIED
ANSWERS(NEW!!!)(NEW!!!)
What is science? (4 features of the scientific method) - ANSWER>>>1. Empirical
2. Deterministic
3. Predictive
4. Parsimonious
Empirical - ANSWER>>>based on data
Deterministic - ANSWER>>>Obeys the laws of physics
Predictive - ANSWER>>>cause-and-effect relationships
Parsimonious - ANSWER>>>use the simplest explanation possible
semitone - ANSWER>>>smallest distance between two pitches (half step)
How many semitones are in one octave? - ANSWER>>>12
How many semitones are in two octaves? - ANSWER>>>24
If you want to go up one octave, you ______ the frequency. But if you want to
go down an octave, you _____ the frequency. - ANSWER>>>Double, halve
how many hertz is in an octave? - ANSWER>>>There's no fixed number of hertz
between octaves
,sampling rate - ANSWER>>>frequency with which numbers are stored or written
down to represent the analog signal that you're sampling
- measured in Hz (how many samples stored in one second)
Nyquist frequency - ANSWER>>>half the sample rate
represents the highest frequency that your recording can accurately reproduce
when you play it back
ex. if you want to go up to 10 kHz, you have to double that number to choose a
sample frequency
sampling theorem - ANSWER>>>gives the minimum sampling rate which allows
the original signal to be reconstructed perfectly
aliasing - ANSWER>>>one sound is misrepresented as another
another concept to think about when choosing a sample rate
if you record a signal at a too-slow sample rate, there will be things happening
in the original signal that occur between the samples or snapshots you take
(inaccurately records the original signal)
filtering before digitizing prevents this (using a low-pass filter for anti-aliasing)
Example sampling: If the data is 5 kHz, you should sample at ______ kHz. -
ANSWER>>>10
How does sampling rate relate to playback quality? - ANSWER>>>The more
samples you take, the better chance you have of representing the original
signal.
what does a filter do? - ANSWER>>>removes certain things you don't want
allow you to be selective in what frequencies come through
filter types - ANSWER>>>high pass
low pass
band pass
, band reject
high pass filter - ANSWER>>>Only allows high frequencies to pass through.
low pass filter - ANSWER>>>Only allows low frequencies to pass through. blocks
high frequencies
band reject filter - ANSWER>>>Rejects or attenuates a band of frequencies, but
allows high and low frequencies to pass through.
band pass filter - ANSWER>>>a specified range of frequencies between the low-
and high-pass cutoff frequencies to be passed effectively.
time domain display - ANSWER>>>x-axis: time
y-axis: amplitude
waveform
represents sound directly
air pressure changes over time
frequency domain display - ANSWER>>>x-axis: frequency
y-axis: power or amplitude
spectrum
shows individual harmonic components
also shows the relative proportions of each component
- peaks represent the individual harmonic components represented in this voice
signal
types of spectra - ANSWER>>>line spectrum
FFT (Fast Fourier Transform)
LPC (Linear Predictive Coding)
line spectrum - ANSWER>>>shows the frequency components of a periodic
sound
