Octave Band Frequencies
The audible frequency range can be separated into unequal segments called octaves.
An octave higher is a doubling of the octave band frequency. Octave bands can be separated into three ranges - referred to as one-third-octave bands.
Octave Bands
listen to the sound! - touch and click the frequency below! | ||
---|---|---|
Lower Band Limit (Hz) | Center Frequency (Hz) | Upper Band Limit (Hz) |
11 | 16 | 22 |
22 | 31.5 | 44 |
44 | 63 | 88 |
88 | 125 | 177 |
177 | 250 | 355 |
355 | 500 | 710 |
710 | 1000 | 1420 |
1420 | 2000 | 2840 |
2840 | 4000 | 5680 |
5680 | 8000 | 11360 |
11360 | 16000 | 22720 |
The "one-third-octaves" have been standardized for scientific instruments commonly used for tasks like to determine NC-criterion and similar.
Third Octave Bands
listen to the sound! - touch and click the frequency below! | ||
---|---|---|
Lower Band Limit (Hz) | Center Frequency (Hz) | Upper Band Limit (Hz) |
11.2 | 12.5 | 14.1 |
14.1 | 16 | 17.8 |
17.8 | 20 | 22.4 |
22.4 | 25 | 28.2 |
28.2 | 31.5 | 35.5 |
35.5 | 40 | 44.7 |
44.7 | 50 | 56.2 |
56.2 | 63 | 70.8 |
70.8 | 80 | 89.1 |
89.1 | 100 | 112 |
112 | 125 | 141 |
141 | 160 | 178 |
178 | 200 | 224 |
224 | 250 | 282 |
282 | 315 | 355 |
355 | 400 | 447 |
447 | 500 | 562 |
562 | 630 | 708 |
708 | 800 | 891 |
891 | 1000 | 1122 |
1122 | 1250 | 1413 |
1413 | 1600 | 1778 |
1778 | 2000 | 2239 |
2239 | 2500 | 2818 |
2818 | 3150 | 3548 |
3548 | 4000 | 4467 |
4467 | 5000 | 5623 |
5623 | 6300 | 7079 |
7079 | 8000 | 8913 |
8913 | 10000 | 11220 |
11220 | 12500 | 14130 |
14130 | 16000 | 17780 |
17780 | 20000 | 22390 |
Wavelength
The wavelength depends on the speed of sound and can be calculated as
λ = c / f (2)
where
λ = wavelength (m)
c = speed of sound (m/s)
f = frequency (s-1, Hz)
Sound velocity depends on the density of the air and the air temperature. Typical value for speed of sound is 343 m/s for temperature 20oC.
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