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 27.5 Hz sound like?
27.5 Hz is a sub-bass frequency. It is a very deep sub-bass tone that you feel in your chest as much as hear. Small speakers struggle to reproduce it; good headphones or a subwoofer will.
A 27.5 Hz sound wave completes 27.5 cycles every second, so one cycle lasts 36.4 ms. In air at 20 °C, where sound travels at about 343 m/s, each wave is 12.47 m (40.92 ft) long; in water it stretches to 53.85 m because sound moves about 4.3 times faster there.
Musically, 27.5 Hz is almost exactly A0 (27.5 Hz) in standard A440 tuning. Doubling it to 55 Hz raises the pitch by one octave; halving it to 13.75 Hz lowers it by one.
Wavelength of 27.5 Hz in different materials
| Medium | Speed of sound | Wavelength |
|---|---|---|
| Air (20 °C) | 343 m/s | 12.47 m |
| Fresh water | 1,481 m/s | 53.85 m |
| Seawater | 1,500 m/s | 54.55 m |
| Helium | 1,007 m/s | 36.62 m |
| Steel | 5,960 m/s | 216.73 m |
| Glass | 5,640 m/s | 205.09 m |
Harmonics and octaves
Real instruments playing 27.5 Hz also produce harmonics at whole-number multiples of the fundamental. Their relative strength gives each instrument its timbre.
Which animals can hear 27.5 Hz?
Cannot hear it
Dogs, Cats, Horses, 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, Catfish, Tuna, Greater wax moths
Instruments and voices that can play 27.5 Hz
Frequently asked questions
What does 27.5 Hz sound like?
It is a very deep sub-bass tone that you feel in your chest as much as hear. Small speakers struggle to reproduce it; good headphones or a subwoofer will.
Can humans hear 27.5 Hz?
Yes. 27.5 Hz is inside the typical human hearing range of 20 Hz to 20 kHz.
What musical note is 27.5 Hz?
27.5 Hz is almost exactly A0, which is 27.5 Hz in standard A440 tuning.
What is the wavelength of 27.5 Hz?
About 12.47 m in air at 20 °C and 53.85 m in water.
Can dogs hear 27.5 Hz?
No – dogs hear roughly 67 Hz to 45,000 Hz.