Characteristics of Sound
Home Up Nature of Sound Waves Simple Harmonic Motion Characteristics of Sound Spectrum and Octave Band Strength of Sound Sound Pressure Level Sound Power Level Sound Intensity Level Free Field Manipulation with Decibels


3. Characteristics of Sound

A sound can be characterized by the following three quantities:

(i) Pitch.

(ii) Quality.

(iii) Loudness.

Pitch is the frequency of a sound as perceived by human ear. A high frequency gives rise to a high pitch note and a low frequency produces a low pitch note. Figure 2 shows the frequencies of same common sounds.


Figure 2 Frequency and Wavelength of Everyday Sound


A pure tone is the sound of only one frequency, such as that given by a tuning fork or electronic signal generator.

The fundamental note has the greatest amplitude and is heard predominantly because it has a larger intensity. The other frequencies such as 2fo, 3fo, 4fo, ............. are called overtones or harmonics and they determine the quality of the sound.

Loudness is a physiological sensation. It depends mainly on sound pressure but also on the spectrum of the harmonics and the physical duration.