Video narration
Are infrasound, ultrasound, and supersonic just three steps up the same pitch ladder? Think of a deep bass note and a sharp whistle: one sounds low, the other high. That difference is pitch, tied to how often a sound wave vibrates each second. For people, the usual hearing range is roughly 20 to 20,000 hertz, though the limits are approximate and vary from person to person. Infrasound sits below that range; audible sounds fall within it; ultrasound sits above it, too high in frequency for us to hear. But supersonic is different. Ultrasound is about how often a wave vibrates. Supersonic is about how fast something moves: faster than sound through the surrounding medium. So these words don't mark three pitches on one ladder. They describe two different measurements: frequency and speed. No. Ultrasound is too high in frequency for us to hear; supersonic means moving faster than sound.