Loudness and Intensity
Loudness is a measure of which a sound can be differentiated from another one, that has the same frequency. Loudness or softness depends on the amplitude.
Loud sound travels long-distance than as loudness or soundness is associate with higher energy.
Sound decreases as we move away from the source as the amplitude decreases.
Figure 3: Soft and Loud Sound – Shape of the wave is the same
The shape of a wave of loud sound and the soft sound remains the same.
The loudness of the sound relies on the intensity of the sound wave.
- The intensity of sound depends on:
- The amplitude of the source sound
- Distance from source
- Source Surface Area (Size of Speaker diaphragm)
- Medium’s Density (Air, Water etc)
- The unit of sound is the decibel(dB). It is named after the inventor of Telephone – Alexander Graham Bell.
Figure 4: Intensity of level of Sounds in different environments
Pitch is the characteristics of sound, it is differentiated as it is shrill or base.
High pitch sound is sharp or shrill and low pitch sound is flat.
Two sounds from the same musical instrument with the same amplitude will differ when their vibration are of different frequency.
Figure 5: Longitudinal Nature of Sound
Timbre or Quality
Timbre is the nature which differentiates two sounds of the same loudness and pitch emitted by two different instruments.
A sound of only one or single frequency is called a tone.
Several tones are called a note.