# Sound

At each sample (horizontal axis), the amplitude is measured (vertical axis) and converted into binary so that is can be stored on a computer.

 Time 1 2 3 4 5 6 Amplitude 14 6 7 9 11 5 Binary 1110 0110 0111 1001 1011 0101

As 15 different amplitudes are available, 4 bits are required to represent the different options. The file size for this sample is 4 (number of bits required per sample) * 6 number of samples) = 24 bits.

If only 8 amplitudes were available, only 3 bits would be required to represent the different  options. The file size would be 3 (number of bits required per sample) * 6 number of samples) = 18 bits.

### Common Questions

Q. What is meant by the sample rate?

A. The sample rate is the frequency at which samples are taken from the sound wave. Similar to processor speed, this is measured as frequency per second. CD quality sound is measured 44,100 times per second or 44,100 Hz or 44.1MHz.

Q. What is meant by the sample resolution (or bit depth) in sound sampling?

A. This refers to the number of bits required to represent each sample of sound. CD quality sound uses 16 bit samples, meaning 65,356 different options per sample.

Q. What is meant by bit rate in sound sampling?

A. Bit rate refers to the number of bits available per second in the sample (Sample Rate * Sample Resolution).