CTS Audio

Question 1

Audio conference data may travel over what transport mediums?

Answer 1

ISDN, IP, POTS

Question 2

An audio conference usually includes what, besides mics?

Answer 2

Line or acoustic echo-cancellation

Question 3

Audio conferences pic up sounds how

Answer 3

A single POD (mic and speaker) or individual mics.

Question 4

The subjective perception of sound is…

Answer 4

Loudness. (yes, poorly worded question)

Question 5

Define decibel

Answer 5

a base 10 logarithmic relationship of a power ratio between two numbers

Question 6

Decibels can be used for what?

Answer 6

Voltage (V), distance, sound pressure (SPL), power (W).

Question 7

Threshold of hearing (dB)

Answer 7

0 dB

Question 8

Very quiet room (dB)

Answer 8

30 dB (.00063 Pa)

Question 9

Office cubicle (dB)

Answer 9

55 dB

Question 10

Normal conversation (dB)

Answer 10

70 dB

Question 11

Yelling (dB)

Answer 11

85 dB (.355 Pa)

Question 12

Rock concert (dB)

Answer 12

115 dB

Question 13

Pain (dB)

Answer 13

130 dB (63 Pa)

Question 14

Smallest dB change a human can hear

Answer 14

1 dB

Question 15

Smallest noticeable volume change (dB)

Answer 15

3dB

Question 16

A _________ dB change is subjectively twice or half as loud.

Answer 16

10 dB

Question 17

If you increase the power (W) by 5dB how much will the loudness (SPL) increase?

Answer 17

5 dB! dB changes in distance, voltage, or power will result in the same dB change in SPL

Question 18

dB reference levels: 0 dB SPL =

Answer 18

.00002 Pa

Question 19

dB reference levels: 0 dBV =

Answer 19

1 V (consumer electronics)

Question 20

dB reference levels: 0 dBu =

Answer 20

.775 V (ProAV electronics)

Question 21

dB reference levels: 0 dBW =

Answer 21

1 W

Question 22

dB reference levels: 0 dBm =

Answer 22

.001W or 1 mW