Frequency
1000 Hz
Period
1.00 ms
Wavelength (air)
34.3 cm
Zone
Hearing range
Volume
50%
Quick:
The normal human ear can detect sound frequencies between 20 Hz and 20 000 Hz (20 kHz). This range varies with age — high-frequency sensitivity declines from around 20 years old. The ear is most sensitive between 2 kHz and 5 kHz.
Frequency is the number of complete oscillations (cycles) per second, measured in Hertz (Hz). Higher frequency = higher pitch. Doubling frequency raises pitch by one octave.
Sound travels at approximately 343 m/s in air at 20°C. The wavelength gets shorter as frequency increases — a 20 Hz wave is 17 m long; a 20 kHz wave is only 1.7 cm.
Frequencies below 20 Hz are called infrasound. Humans cannot hear these but can sometimes feel them. Produced by earthquakes, large machinery, and some animals (elephants, whales).
Frequencies above 20 kHz are called ultrasound. Used in medical imaging (1–20 MHz), sonar, and by bats and dolphins for echolocation. Dogs can hear up to ~65 kHz.
Loudness is measured in decibels (dB). The threshold of hearing is 0 dB; normal conversation is ~60 dB; a jet engine is ~140 dB. The scale is logarithmic — every +10 dB is a perceived doubling of loudness.
This simulation produces audible tones. Use at a comfortable volume. The 15–20 kHz range may not be audible on low-quality speakers or to older listeners.