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.
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. [ DOI | 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. Traunmüller. 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.