FREQTOAUD Converts frequencies (Hz) to auditory scale units
Usage: aud = freqtoaud(freq,scale);
FREQTOAUD(freq,scale) converts values on the frequency scale (measured
in Hz) to values on the selected auditory scale. The value of the
parameter scale determines the auditory scale:
'erb' A distance of 1 erb is equal to the equivalent rectangular
bandwidth of the auditory filters at that point on the
frequency scale. The scale is normalized such that 0 erbs
corresponds to 0 Hz. The width of the auditory filters were
determined by a notched-noise experiment. The erb scale is
defined in Glasberg and Moore (1990). This is the default.
'mel' The mel scale is a perceptual scale of pitches judged by
listeners to be equal in distance from one another. The
reference point between this scale and normal frequency
measurement is defined by equating a 1000 Hz tone, 40 dB above
the listener's threshold, with a pitch of 1000 mels.
The mel-scale is defined in Stevens et. al (1937).
'mel1000' Alternative definition of the mel scale using a break
frequency of 1000 Hz. This scale was reported in Fant (1968).
'bark' The bark-scale is originally defined in Zwicker (1961). A
distance of 1 on the bark scale is known as a critical
band. The implementation provided in this function is
described in Traunmuller (1990).
'erb83' This is the original defintion of the erb scale given in
Moore. et al. (1983).
'freq' Return the frequency in Hz.
If no flag is given, the erb-scale will be selected.
References:
S. Stevens, J. Volkmann, and E. Newman. A scale for the measurement of
the psychological magnitude pitch. J. Acoust. Soc. Am., 8:185, 1937.
E. Zwicker. Subdivision of the audible frequency range into critical
bands (frequenzgruppen). J. Acoust. Soc. Am., 33(2):248--248, 1961.
[1]http ]
G. Fant. Analysis and synthesis of speech processes. In B. Malmberg,
editor, Manual of phonetics. North-Holland, 1968.
B. R. Glasberg and B. Moore. Derivation of auditory filter shapes from
notched-noise data. Hearing Research, 47(1-2):103, 1990.
H. Traunmuller. Analytical expressions for the tonotopic sensory scale.
J. Acoust. Soc. Am., 88:97, 1990.
B. Moore and B. Glasberg. Suggested formulae for calculating
auditory-filter bandwidths and excitation patterns. J. Acoust. Soc.
Am., 74:750, 1983.
References
1. http://link.aip.org/link/?JAS/33/248/1
Url: http://ltfat.github.io/doc/auditory/freqtoaud.html
See also: freqtoaud, audspace, audfiltbw.
Package: ltfat