Distortion

Question 1

Define distortion as used in this course.

Answer 1

Changes in a sound

Question 2

What is frequency distortion? Draw an example.

Answer 2

frequencies change as they pass through a system
see drawing

Question 3

How does signal duration affect the spectrum of a pure tone?

Answer 3

a shorter signal leads to spectral splatter and the longer the signal gets the closer it gets to a pure tone

Question 4

What are the min specifications for pure tone testing

Answer 4

Signal duration of at least 200 msec

Rise/fall time of at least 20 msec

Question 5

Define rise and fall time.

Answer 5

Rise time is the time it takes to reach full amplitude
Fall time is the time it takes to go from full amplitude to zero

Question 6

What is transient distortion?

Answer 6

when a sound is suddenly turned on or off - leads to spectral splatter

Question 7

What are the minimum specifications for pure tone testing in terms of presentation duration and rise/fall time?

Answer 7

presentation - 200 msec
rise/fall - 20 msec each

Question 8

What is a linear system? What is a nonlinear system?

Question 9

How is amplitude distortion caused?

Question 10

What is harmonic distortion?

Question 11

What are distortion products?

Answer 11

extra sounds that are in the signal

Question 12

What is intermodulation distortion?

Answer 12

same as harmonic but with multiple tones

Question 13

What is input and examples

Answer 13

characteristics of the sound itself
ex: rocket making sound, test signal in HA, sound arriving at the cochlea

Question 14

What is output and examples

Answer 14

what it is doing on the other side
ex: result of sound going through the air, whatever comes out of the HA, sound as it is coded going up to the brain