We hear different kinds of sounds every day. We hear the sound of vehicles, the sound of the market, the sound of rainfall, the sound of musical instruments, etc every day. Some of these sounds are sweet and some are harsh. If we judge by our sensation the sweet sounds are musical sounds. It is a tone with characteristics such as controlled pitch and timbre. Musical sounds are distinguished from noises in that they are composed of regular, uniform vibrations, while noises are irregular and disordered vibrations.
The characteristics of musical sound:
One musical tone is distinguished from another on the basis of pitch, intensity, or loudness, and quality, or timbre. The three characteristics of musical sounds are-
(1) Loudness or Intensity, (2) Pitch, and (3) Quality or Timbre.
- Loudness or Intensity:
Loudness or intensity means how loud the sound is. Intensity is the amount of sound energy flowing per second per unit area perpendicular to the direction of propagation of sound. The loudness of musical sound is related to the intensity of the sound the higher is the intensity, the higher will be the loudness. In the SI system of the unit, the unit of intensity of sound is Wm-2.
The characteristic of musical sound by which we can differentiate between a shrill sound and a dull sound of the same intensity is called pitch. Pitch describes how high or low a tone is and depends upon the rapidity with which a sounding body vibrates, i.e., upon the frequency of vibration. It is the characteristics of a musical sound which depends upon the frequency. It depends on the frequency of the source. With the increase of frequency, the pitch becomes higher making the note more and more shrill. The sound with low frequency is low pitch able sound and the sound with high frequency is high pitch able sound. Greater the frequency of a musical note, higher is the pitch. It is the sensation conveyed to the brain by the sound waves falling on the ears.
- Quality or Timbre:
The characteristic of musical sound by which we can differentiate between two sounds of the same intensity and pitch is called quality or timbre. It measures the complexity of sound. The quality of sound depends upon the number and intensity of harmonics. It is determined by the number of harmonics present, their order, and relative intensities.
Why the voice of men is deep and the voice of women and children is sharp?
There are two membranes in our vocal which are known as vocal cords. The sound is produced due to the vibration of vocal cords and so people can speak. Due to the different harmonics present in the voices, we characteristics of sound are called Quality or Timber.
The vocal cords of adult men become thick as they age but the vocal cords of children and women are not thick. For this, the frequency of voice of the adult men is less and the frequency of voice of women and children is more. So the voice of men is deep but the voice of children and women is sharp.