Beat frequency refers to the difference in frequency between two sound waves or other periodic waves that are slightly different in frequency. When two waves with slightly different frequencies are played simultaneously, they interfere with each other to produce a pattern of constructive and destructive interference. This interference pattern causes the amplitude of the resulting wave to oscillate at a frequency equal to the difference between the two frequencies.
The beat frequency can be calculated as the absolute value of the difference between the two frequencies:
beat frequency = |f1 – f2|
For example, if two tuning forks with frequencies of 440 Hz and 442 Hz are sounded simultaneously, the beat frequency would be 2 Hz. This beat frequency can be heard as a periodic variation in the loudness or intensity of the resulting sound wave.
Beat frequencies are used in a variety of applications, including musical tuning, radio communication, and the measurement of small frequency differences. In music, beat frequencies can be used to tune instruments or to create musical effects such as vibrato. In radio communication, beat frequencies are used in heterodyne receivers to convert high-frequency signals to a lower frequency that can be more easily detected and processed. In precision measurements, beat frequencies can be used to detect small changes in frequency or to compare the frequencies of two sources. Read More about Beaufort scale.