gen-briefly-explain-beat-frequency-and-one-common-misconception-031b

Briefly explain beat frequency and one common misconception about it.

## Beat Frequency **Beat frequency** is the periodic variation in amplitude (loudness) that occurs when two sound waves of slightly different frequencies interfere with each other. The beats are heard as a "wah-wah-wah" pulsing effect, and the beat frequency equals the **absolute difference** between the two original frequencies: **f_beat = |f₁ - f₂|** For example, a 440 Hz and 442 Hz tone played together produce 2 beats per second. ## Common Misconception Many people mistakenly believe that beat frequency is a **new sound wave** being created at the difference frequency. In reality, beats are simply an **amplitude modulation effect** caused by constructive and destructive interference. The two original frequencies are still present—they're just causing the combined wave's amplitude to oscillate. Your ear doesn't actually detect a third tone at the beat frequency; instead, you hear the volume of the combined sound rising and falling at that rate.