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What does 640 Hz sound like?
640 Hz is a midrange frequency. It is a clear midrange tone, close to where the human ear does most of its work for speech and melody.
A 640 Hz sound wave completes 640 cycles every second, so one cycle lasts 1.56 ms. In air at 20 °C, where sound travels at about 343 m/s, each wave is 53.6 cm (1.76 ft) long; in water it stretches to 2.31 m because sound moves about 4.3 times faster there.
Musically, 640 Hz is 49 cents above D♯5 (622.25 Hz) in standard A440 tuning. Doubling it to 1,280 Hz raises the pitch by one octave; halving it to 320 Hz lowers it by one.
Wavelength of 640 Hz in different materials
| Medium | Speed of sound | Wavelength |
|---|---|---|
| Air (20 °C) | 343 m/s | 53.6 cm |
| Fresh water | 1,481 m/s | 2.31 m |
| Seawater | 1,500 m/s | 2.34 m |
| Helium | 1,007 m/s | 1.57 m |
| Steel | 5,960 m/s | 9.31 m |
| Glass | 5,640 m/s | 8.81 m |
Harmonics and octaves
Real instruments playing 640 Hz also produce harmonics at whole-number multiples of the fundamental. Their relative strength gives each instrument its timbre.
Which animals can hear 640 Hz?
Can hear it
Humans, Dogs, Cats, Horses, Cows, Sheep, Pigs, Goats, Rabbits, Rats, Gerbils, Guinea pigs, Hedgehogs, Raccoons, Ferrets, Opossums, Chinchillas, Elephants, Bottlenose dolphins, Chickens, Canaries, Budgerigars (parakeets), Cockatiels, Owls, Bullfrogs, Tree frogs, Goldfish, Catfish, Tuna
Cannot hear it
Instruments and voices that can play 640 Hz
Frequently asked questions
What does 640 Hz sound like?
It is a clear midrange tone, close to where the human ear does most of its work for speech and melody.
Can humans hear 640 Hz?
Yes. 640 Hz is inside the typical human hearing range of 20 Hz to 20 kHz.
What musical note is 640 Hz?
640 Hz is 49 cents above D♯5, which is 622.25 Hz in standard A440 tuning.
What is the wavelength of 640 Hz?
About 53.6 cm in air at 20 °C and 2.31 m in water.
Can dogs hear 640 Hz?
Yes – dogs hear roughly 67 Hz to 45,000 Hz.