# Sound

## 09 Characteristics of Sound

A sound has FOUR characteristics

• Loudness
• Pitch
• Quality (or timbre) and
• Intensity.

#### LOUDNESS

• The loudness of sound is a measure of the sound energy reaching the ear per second.
• The loudness of sound is measured in ‘decibel’. It is written as dB.

#### PITCH

• Pitch is that characteristics of sound by which we can distinguish between different sound of the same loudness.
• The pitch of a sound depends on the frequency of vibration.
• The pitch of a sound is directly proportional to its frequency.
• Higher the frequency of sound, higher is the pitch.

#### QUALITY (OR TIMBRE)

• Quality (or timbre) is that characteristic of musical sound which enables us to distinguish between the sounds of same pitch and loudness produced by different musical instruments (and different singers).
• The quality (or timbre) of a musical sound depends on the shape of sound wave (or waveform) produced by it.

#### INTENSITY OF SOUND

The amount of sound energy passing each second through a unit area is called the intensity of the wave.