Nature of Sound Waves
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

 

1. Nature of Sound Waves

Sound is one kind of longitudinal wave, in which the particles oscillate to and fro in the same direction of wave propagation. Sound waves cannot be transmitted through vacuum. The transmission of sound requires at least a medium, which can be solid, liquid, or gas.

 

condensation

rarefaction

 

The wavelength, l is the distance between two successive rarefactions or condensations.

 

Figure 1 Propagation of Sound Wave

 

The displacement of any point on the wave, y, along the direction of propagation is related to time by the following formula:

(1)

(2)

(3)

(4)

 

Table 1 shows the velocities of sound in same common media.

Material

Velocity of Sound (m/s)

Air

344

Water

1,372

Concrete

3,048

Glass

3,658

Iron

5,182

Lead

1,219

Steel

5,182

Wood (hard)

4,267

Wood (soft)

3,353

Table 1 Approximate Velocities of Sound in Some Common Media