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What is compression ratio in a typical mp3 audio files?

  1. 4:1
  2. 6:1
  3. 8:1
  4. 10:1
in Multimedia by (29 points) | 2.3k views

2 Answers

+3 votes

Audio is recorded in frequency = 44.1 KHz

While converting to Mp3 16 bits are used to represent one sound signal.

For sake of stereo 2 channels are used.

Hence

2 channels of 16bit audio at 44.1KHz = 2 x 16 x 44,100 = 1,411,200 bits/sec, or 172kbyte/sec

Compression is made at128kbit, or 16kbyte/sec

So, 172 / 16 = 10.75:1 compression

 

Ans is D

by Boss (33k points)
+2 votes
Answer (d)

 

Uncompressed audio as stored on an audio-CD has a bit rate of 1,411.2 kbit/s, so the bitrates 128, 160 and 192 kbit/s represent compression ratios of approximately 11:1, 9:1 and 7:1 respectively.
by Loyal (9.9k points)
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