An Introduction to Beats

Definition of beats

You can hear a fluctuating sound when two items vibrate at different frequencies (soft and loud sound alternatively). This phenomenon is referred to as beats or frequency of sound beats.

or

You can hear a fluctuating sound when two sound waves of slightly differing frequencies approach your ear (soft and loud sound alternatively). Beats are the name for this phenomena. The constructive interference causes the loud sound, whereas the destructive interference causes the quiet sound.

Constructive Interference

When two waves of the same frequency collide in such a way that the crests of one wave collide with the crests of another wave, the interference is said to be constructive.

The amplitude of sound waves is augmented when two sound waves of the same frequency collide in such a way that the peak of one wave hits the crest of another. As a result, the resulting sound is far louder than the original.

Destructive Interference

When two waves of the same frequency collide in such a way that the peak of one wave meets the trough of another, the interference is said to be destructive.

The amplitude of two sound waves of the same frequency are subtracted when the crest of one wave reaches the trough of another. As a result, the resulting sound is far softer than the original.

Beat Frequency

When two sound waves of different frequencies collide, their amplitudes are alternately added and subtracted over a period of time. As a result, the resulting sound intensity changes with time (becomes louder and softer).

Consider two sound waves with different frequencies but the same amplitude moving in the same medium: sound wave 1 and sound wave 2.

A fluctuating sound is produced when these sound waves collide. The crest of sound wave 1 collides with the crest of sound wave 2 for a brief moment. As a result, constructive interference occurs. As a result, the volume of sound increases for a short time.

After some time, however, the crest of sound wave 2 collides with the trough of sound wave 1. As a result, harmful interference occurs. As a result, the sound strength drops for a while.

Similarly, sound intensity rises and decreases in a predictable pattern throughout time. As a result, you alternately hear a quiet and loud sound.

The amplitude of the generated sound wave, unlike the source sound waves, does not remain constant throughout time.

We term waxing of sound when the intensity of sound reaches its peak. We call it the waning of sound when the intensity of sound drops to a minimum.

Beats are the periodic waxing and fading of sound that occurs when two sound waves of roughly equal frequencies collide.

Beat frequency is defined as the difference in frequencies of two waves multiplied by the number of beats produced per second.

Applications of beats

The various applications of beats are:

1.Police radar

2.Doppler pulse detection

3.Subjective tones

4.Multiphonics

Conclusion 

As we conclude that the interference of two waves at the same place in space causes beats. The periodic increase and drop for two sine waves can be seen in this plot of the variation of resultant amplitude with time. When two waves of the same frequency collide in such a way that the crests of one wave collide with the crests of another wave, the interference is said to be constructive.

The amplitude of sound waves is augmented when two sound waves of the same frequency collide in such a way that the peak of one wave hits the crest of another. As a result, the resulting sound is far louder than the original.