Consider an uncompressed stereo audio signal of CD quality which is sampled at 44.1 kHz and quantized using 16 bits. What is required storage space if a compression ratio of 0.5 is achieved for 10 seconds of this audio?

Consider an uncompressed stereo audio signal of CD quality which is sampled at 44.1 kHz and quantized using 16 bits. What is required storage space if a compression ratio of 0.5 is achieved for 10 seconds of this audio? Correct Answer 860 KB

The correct answer is option 3.

Key Points

Frequency = 44.1k Hz = 44100 bits per second, Compression ratio=0.5
This is a stereo audio signal, it will need 2 channels. 16 bits used for quantized(converting to MP3)
Bit Rate = number channels × bits × frequency = 2 × 16 × 44100 = 1411200 bps
Compressed Bit Rate = 0.5 × 1411200 = 705600 bps
For 10 seconds,
Bit rate=10 × 705600 bits = 7056000 bits
= 882000 Bytes(7056000/8)
= 882 KB (882000/1000)
∴ Hence the correct answer is 860 KB.