Start with your device volume low. Very low tones may be inaudible on phone or laptop speakers; very high tones can be uncomfortable on headphones.
What does 18 Hz sound like?
18 Hz is a infrasound frequency. It is infrasound – below the roughly 20 Hz lower limit of human pitch perception. At high levels it is felt as pressure, fluttering or vibration rather than heard as a tone, and phone or laptop speakers cannot reproduce it at all.
A 18 Hz sound wave completes 18 cycles every second, so one cycle lasts 55.6 ms. In air at 20 °C, where sound travels at about 343 m/s, each wave is 19.06 m (62.52 ft) long; in water it stretches to 82.28 m because sound moves about 4.3 times faster there.
Musically, 18 Hz is 34 cents below D0 (18.35 Hz) in standard A440 tuning. Doubling it to 36 Hz raises the pitch by one octave; halving it to 9 Hz lowers it by one.
Natural infrasound comes from earthquakes, volcanoes, ocean waves, wind and thunder; whales and elephants use it to communicate across long distances.
Wavelength of 18 Hz in different materials
| Medium | Speed of sound | Wavelength |
|---|---|---|
| Air (20 °C) | 343 m/s | 19.06 m |
| Fresh water | 1,481 m/s | 82.28 m |
| Seawater | 1,500 m/s | 83.33 m |
| Helium | 1,007 m/s | 55.94 m |
| Steel | 5,960 m/s | 331.11 m |
| Glass | 5,640 m/s | 313.33 m |
Harmonics and octaves
Real instruments playing 18 Hz also produce harmonics at whole-number multiples of the fundamental. Their relative strength gives each instrument its timbre.
Which animals can hear 18 Hz?
Cannot hear it
Humans, Dogs, Cats, Horses, Cows, Sheep, Pigs, Goats, Rabbits, Rats, Mice, Gerbils, Guinea pigs, Hedgehogs, Raccoons, Opossums, Chinchillas, Bats, Beluga whales, Bottlenose dolphins, Chickens, Canaries, Budgerigars (parakeets), Cockatiels, Owls, Bullfrogs, Tree frogs, Goldfish, Catfish, Tuna, Greater wax moths
Frequently asked questions
What does 18 Hz sound like?
It is infrasound – below the roughly 20 Hz lower limit of human pitch perception. At high levels it is felt as pressure, fluttering or vibration rather than heard as a tone, and phone or laptop speakers cannot reproduce it at all.
Can humans hear 18 Hz?
No. 18 Hz is below the ~20 Hz limit of human pitch perception; very loud infrasound can be felt as vibration.
What musical note is 18 Hz?
18 Hz is 34 cents below D0, which is 18.35 Hz in standard A440 tuning.
What is the wavelength of 18 Hz?
About 19.06 m in air at 20 °C and 82.28 m in water.
Can dogs hear 18 Hz?
No – dogs hear roughly 67 Hz to 45,000 Hz.