Flashcards in Tutorial week 10 Deck (18):
1
what do you call a voltage, which varies over time
waveform
2
The waveform of a pure tone is called a ___________
a sine wave
3
How is a complex waveform related to simple sine waves?
a complex waveform can be broken down into simple sine waves or built up from them
4
What is the frequency of a waveform with 4 msec between peaks?
250Hz
5
You heard how a pure tone (of e.g. 500Hz) and a square wave or a sawtooth of the same frequency have a very different sound; the sine wave has a
"smooth" pure sound whereas the sawtooth has a much "rougher" sound.
That "quality" of the sound is called ________. But the pitch (related to the
fundamental frequency) of all three waveforms is the same.
timbre
6
How large a difference in frequency was needed for you to detect a difference
between that (variable frequency) test tone and a 500Hz tone?
under optimal conditions (not true here) good observers can detect the difference between 500 and 502 Hz
7
Low-pass filtering a stimulus removes what frequencies.....?
Low pass filtering removes high frequencies
8
And what does the sound sound like as you do so.......?
sounds become “muffled” or “blurry”
9
Low-pass filtering of speech has the same effect. Which group of people
would experience such low-pass filtered speech....?
old people (such as you- you’re not exactly 13 anymore, are you?)
10
what does Presbycusis mean
Presbycusis, from Greek presbys “elder” + akousis “hearing”, is age-related hearing loss.
11
For frequencies above ______Hz, threshold gets worse very rapidly.
15000 Hz,
12
Studies of _______ and other peoples living away from industrialised society suggests that they suffer less hearing loss
Easter Islanders
13
what do you call the smallest bone in the body and where is it located?
stirrup, inner ear
14
_____ are sensitive to frequencies much higher than humans are.
Dogs
15
__________ is a change in air pressure. they are very small changes of a large
steady pressure
sounds
16
A sound is a wave of __________ that moves away from the sound source slowly - with a speed of about 340 m/sec whereas light is a wave of
_________ with a speed about one million times greater than
sound: 300,000 km/sec.
1. mechanical disturbance
2. electromagnetic radiation
17
Sound is change in air pressure and the measure of pressure is force per unit area. The units of force are ________ or _______. But since sound is a change in air pressure, to measure the amplitude of a sound it is necessary to
measure the extent of the change or variation. As you know from statistics, the ________ is a measure of variation and that is essentially how the
amplitude of sound is measured.
1. pascals (Pa)
2. micropascals (μPa)
3. standard deviation
18