Lesson 21 Flashcards
1
Q
When you cup your hand behind the ear, sound
A
increase by 5-8 dB
2
Q
The first patent for a telephone type hearing instrument was
A
1892
3
Q
The first electric hearing instrument
A
collected and amplified sound
4
Q
The carbon granule microphone
A
caused static and fading with body movement
5
Q
Desk and suitcase sized hearing instruments, popular in the 1920’s had more gain and clarity because of
A
vacuum tube amplifiers
6
Q
Wearable instruments were a result of
A
the miniature vacuum tube
7
Q
Crystal microphones and receivers
A
are very fragile
8
Q
A FET changed the high impedance problems of the
A
ceramic microphone
9
Q
Magnetic microphones
A
have a godd frequency response in the speech range
10
Q
The miniature vacuum tube was introduced in about
A
1938
