The critical band calculator gives the ERB, the ERB-number, the Bark value, the critical bandwidth and the mel value of a frequency, the main scales used in psychoacoustics.
How the calculation works
- Enter the frequency in hertz.
- Read the ERB and the critical bandwidth.
- Read the Bark, ERB-number and mel values.
Example
At 1000 Hz the ERB is 24.7 × (4.37 × 1 + 1) = 132.6 Hz, on the ERB-number scale 21.4 × log₁₀(5.37) = 15.62. The Bark value is 8.51, the Zwicker critical bandwidth is 162 Hz and the pitch is 2595 × log₁₀(1 + 1000 / 700) = 1,000 mel.
Why it matters
The calculator helps students of acoustics, audio engineering and speech technology, who design filter banks, codecs and masking models, and hearing scientists who compare the frequency resolution of the ear.
Good to know
These scales are descriptions of the frequency resolution of the ear and they differ in method and result, so the choice of a scale depends on the application. Audio codecs such as MP3 use the Bark scale to estimate which sounds are masked and can be dropped, speech recognition uses the mel scale to approximate pitch perception, and models of auditory filters in research use the ERB scale, which fits the data on masking at low levels. The ERB formula was fitted to young listeners with normal hearing at moderate levels, and the filters broaden at high levels and in hearing loss, which makes it harder to separate sounds. People with sensorineural hearing loss often have auditory filters two to four times wider, which explains much of their difficulty in noise. The values here are for the center of the band and they are smooth functions of frequency, with no sharp boundaries between bands. The mel scale has several variants with different constants, and the one given here is the most common.
Related tools
The Greenwood calculator maps frequency to place in the cochlea, the loudness calculator converts phons to sones, the music interval calculator treats pitch ratios and the ear canal calculator treats the resonance of the ear.