Chapter 7

Question 1

Which part of the human auditory system works like a Fourier analyzer in separating out the individual frequency components of complex waveforms?

Answer 1

the basilar membrane in the cochlea

Question 2

Suppose you have a complex wave composed of two frequencies. If the lower frequency is 1500 Hz, and the higher frequency is one octave above the lower frequency, what is the higher frequency in Hz?

Answer 2

3,000

Question 3

Spectrograms are plots of sound in three dimensions. Match each axis to its dimension.
x:
y:
z:

Answer 3

• time
• frequency
• amp/magnitude

Question 4

There are different ways of making the vocal folds vibrate. The usual mode of phonation is call ___ vibration.

Answer 4

Modal

Question 5

How many octaves are in a typical audiogram? (125 Hz to 8000 Hz)

Answer 5

6

Question 6

Human speech contains a broad range of frequencies. In general, the lower frequencies of the speech signal are ____ the higher frequencies.

Answer 6

higher in amplitude than

Question 7

In the cochlea, low frequency sounds are encoded at the ___ , while high frequency sounds are encoded at the ___.

Answer 7

apex
base

Question 8

Suppose you have a complex wave composed of two frequencies. If the higher frequency is 1000 Hz, and the lower frequency is two octaves below the higher frequency, what is the lower frequency in Hz?

Answer 8

250

Question 9

The Discrete Fourier Transform (DFT) is a mathematical method for transforming a ____ into a ____.

Answer 9

time-domain waveform
frequency-domain spectrum

Question 10

If you examine the DFT of a waveform that is of long duration, you can obtain more precise information about the specific frequencies that are present in that signal; however, you have limited information about the time at which those frequencies occurred during the signal.

Answer 10

True

Question 11

Check all of the boxes that accurately describe a wideband spectrogram.

-broad frequency bandwidth
-short time window
-long time window
-narrow frequency bandwidth
-good frequency
-resolution/information
-good time resolution/information

Answer 11

broad frequency bandwidth
short time window
good time resolution/information

Question 12

Check all of the boxes that accurately describe a narrowband spectrogram.
-broad frequency bandwidth
-short time window
-long time window
-narrow frequency bandwidth
-good frequency resolution/information
-good time resolution/information

Answer 12

narrow frequency bandwidth
long time window
good frequency resolution/information

Question 13

In white noise, the lower frequencies are ____ higher frequencies. In pink noise, the lower frequencies ____ than are higher frequencies.

Answer 13

the same amplitude as
of higher amplitude

Question 14

An infinitely short stimulus in time will be infinitely narrow in frequency.

Answer 14

An infinitely short stimulus in time will be infinitely narrow in frequency.

Question 15

When we talk about voice in speech acoustics, what we mean is ___________.
-an idea expressed in thought groups.
-what we sound like when we talk.
-the sound produced by phonation.
-the pitch at which a person sings.

Answer 15

the sound produced by phonation.

Question 16

What frequency is 2 octaves above 1,755 Hz?

Answer 16

7,020

Question 17

Which of the following is true with regards to white noise?
All frequencies have the same amplitude
Only low frequencies are present
Lower frequencies have larger amplitudes than higher frequencies
Only high frequencies are present

Answer 17

All frequencies have the same amplitude

Question 18

A narrowband spectrogram has good
[ Select ]
resolution,
[ Select ]
frequency bandwidth, and a long time window.

Answer 18

frequency
narrow
long