Chapter 6 Flashcards
In analog waveforms, the independent variable (time) can take on a(n) _________ number of time values.
infinite
Suppose you want to record a conversation between two people who are in an airport with lots of other noise. What is the best microphone response pattern for this application?
cardiod
Suppose you want to record speech in a quiet and controlled location. Which of the following is the best microphone response pattern for this application?
omnidirectional
The Nyquist frequency is _______ the sampling rate.
half of
A RCA audio connector has a gender of ___ (female or male) and carries what type of signal?
male, mono signal
Downsampling and upsampling are done to improve sound quality. (T or F)
false
Compressed recordings (e.g., MP3, AAC) should be used for acoustic analysis and maintaining the recording. (T or F)
false
A XLR audio connector has a gender of ___ (female or male) and carries what type of signal?
female, stereo signal
A wall plug is an example of an alternating current or direct current?
alternating current
A battery is an example of an alternating current or direct current?
direct current
Suppose you make a recording and you choose the automatic gain control (AGC) option.
Gain will be variable across recording time
Adjustments to automatic gain control (AGC) occur instantaneously (i.e. without any time lag) when sudden changes in input amplitude occur. (T or F)
false
The process of converting the continuous dependent variable (amplitude) to a discrete set of values.
quantization
To reconstruct a continuous time signal, the sampling rate should be at least two times the maximum frequency in the signal
sampling theorem
Change in amplitude prior to digitization
gain
The loudest sound recorded under the maximum sound level that the recorder is able to record
saturated recording
To reduce external noise, we could:
use a directional microphone, use a sound barrier, or move to a sound treated booth
When the peak amplitude of a signal is larger than the upper end of a recorder’s dynamic range, this will result in a ____ (saturated, optimal, over-modulated, or under-modulated) recording, which means the the recorded waveform will be___(aliasing, under-sampled, over-sample, peak clipped, or saturated)
over-modulated, peak clipped
The MP3 digital file format (file extension .mp3) is best described as?
compressed lossy
Frequency of the alternating current in North America is…
60Hz
Dynamic range
- A single value
- The ratio of the highest to lowest levels a system can process without distortion
Sound recordings are typically played back through two loudspeakers. What type of recordings send the identical signal to two loudspeakers?
mono
