Ultrasonic waves have the following wavelength:

The wavelengths of audible sound frequencies (20 Hz–20 kHz) are thus approximately 17 m and 17 mm, respectively. Bats use slightly higher frequencies to resolve targets smaller than 17 mm. The wavelengths of audible sound are significantly longer than those of visible light.

Ultrasonic waves have a frequency greater than 20 kHz, which is higher than the audible range. Because energy increases with frequency in waves, ultrasonic sound has more energy than audible sound.