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What does 665 Hz sound like?
665 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 665 Hz sound wave completes 665 cycles every second, so one cycle lasts 1.5 ms. In air at 20 °C, where sound travels at about 343 m/s, each wave is 51.6 cm (1.69 ft) long; in water it stretches to 2.23 m because sound moves about 4.3 times faster there.
Musically, 665 Hz is 15 cents above E5 (659.26 Hz) in standard A440 tuning. Doubling it to 1,330 Hz raises the pitch by one octave; halving it to 332.5 Hz lowers it by one.
Wavelength of 665 Hz in different materials
| Medium | Speed of sound | Wavelength |
|---|---|---|
| Air (20 °C) | 343 m/s | 51.6 cm |
| Fresh water | 1,481 m/s | 2.23 m |
| Seawater | 1,500 m/s | 2.26 m |
| Helium | 1,007 m/s | 1.51 m |
| Steel | 5,960 m/s | 8.96 m |
| Glass | 5,640 m/s | 8.48 m |
Harmonics and octaves
Real instruments playing 665 Hz also produce harmonics at whole-number multiples of the fundamental. Their relative strength gives each instrument its timbre.
| Harmonic | Frequency | Nearest note |
|---|---|---|
| 1× (fundamental) | 665 Hz | E5 |
| 2× | 1.33 kHz | E6 |
| 3× | 1.995 kHz | B6 |
| 4× | 2.66 kHz | E7 |
| 5× | 3.325 kHz | G♯7 |
| 6× | 3.99 kHz | B7 |
| 7× | 4.655 kHz | D8 |
| 8× | 5.32 kHz | E8 |
Which animals can hear 665 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 665 Hz
Frequently asked questions
What does 665 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 665 Hz?
Yes. 665 Hz is inside the typical human hearing range of 20 Hz to 20 kHz.
What musical note is 665 Hz?
665 Hz is 15 cents above E5, which is 659.26 Hz in standard A440 tuning.
What is the wavelength of 665 Hz?
About 51.6 cm in air at 20 °C and 2.23 m in water.
Can dogs hear 665 Hz?
Yes – dogs hear roughly 67 Hz to 45,000 Hz.