The bandwidth of a speech signal is from 50 Hz through to 10

The bandwidth of a speech signal is from 50 Hz through to 10 kHz and that of a music signal is from 15 Hz through to 20 kHz. You want to digitize these signals using the Nyquist criterion.

• What is the bit rate produced for the speech signal if 12 bits are used per sample?

• Perform the same for the music signal when 16 bits per sample are used.

• How many megabytes of storage do you need for 10 minutes of stereophonic music?

Solution

Given

Bandwidth of speech signal = 50Hz to 10KHz

Bandwidth of a music signal = 15Hz to 20KHz

Bit rate for Speech Signal:

For the speech signal 12 bits are used for sample.

Speech signal must be sampled at 20 kHz.

So its bit rate = 12 * 20 = 240 Kbps

Bit rate for Music Signal:

For the music signal 16 bits are used for sample.

Music signal must be sampled at 40 kHz.

Thus its bit rate = 16 * 40 = 640 Kbps

Storage for 10minutes of stereophonic music:

10 minute of mono music requires 10*60*640K = 384 Mbits = 48 Mbytes.

Space required for stereophonic music= 48*2 = 96 Mbytes.