Frequency selectivity for frequencies below 100 Hz: Comparisons with mid-frequencies

Abstract

Auditory filter shapes were derived for signal frequencies (f(s)) between 50 and 1000 Hz, using the notched-noise method. The masker spectrum level (N(0)) was 50 dB (re 20 μPa). For f(s) = 63 and 50 Hz, measurements were also made with N(0) = 62 dB for the lower band. The data were fitted using a rounded-exponential filter model, with special consideration of the filtering effects of the middle-ear transfer function (METF) at low frequencies. The results showed: (1) For very low values of f(s), the lower skirts of the filters were only well defined when N(0) = 62 dB for the lower band; (2) the sharpness of both sides of the filters decreased with decreasing f(s); (3) the dynamic range of the filters decreased with decreasing f(s); (4) the equivalent rectangular bandwidth of the filters decreased with decreasing f(s) down to f(s) = 80 Hz, but increased for f(s) below that; (5) the assumed METF, which includes the shunt effect of the helicotrema for frequencies below 50 Hz, increasingly influenced the low-frequency skirt of the filters as f(s) decreased; and (6) detection efficiency worsened with decreasing f(s) for f(s) between 100 and 500 Hz, but improved slightly below that.

Resolvability of components in complex tones and implications for theories of pitch perception

“…However, the bandwidths of the filters on the basilar membrane increase with increasing center frequency (von Békésy, 1960;Robles and Ruggero, 2001). Similarly, the bandwidths of the auditory filters as measured psychophysically increase with increasing center frequency (Glasberg and Moore, 1990), from about 30 Hz at very low frequencies (Jurado and Moore, 2010) to about 1600 Hz at very high frequencies (Zhou, 1995). As a result, the lower harmonics in a complex tone are "separated out" or "resolved" on the basilar membrane; each gives rise to a distinct localized peak along the tonotopic axis.…”

“…Discrimination of F0 worsens when the number, N, of the lowest harmonic in a complex tone increases above about 7, reaching a plateau when N is about 14e15 (Hoekstra and Ritsma, 1977;Houtsma and Smurzynski, 1990;Kaernbach and Bering, 2001;Bernstein and Oxenham, 2003;Moore et al, 2006a). The worsening as N is increased from 7 to about 14 has been interpreted by some researchers as resulting from a progressive reduction of the ability to resolve the components in the complex tone (Houtsma and Smurzynski, 1990;Shackleton and Carlyon, 1994).…”

“…basilar membrane by the interference of several harmonics (temporal fine structure appears not be to involved, since frequency shifting all of the harmonics by an equal amount in Hertz does not change the perceived pitch when all harmonics are above the 14th; Moore and Moore, 2003b). Tones containing only very high harmonics have a less distinct pitch than tones with low harmonics, and changes in their F0 are harder to discriminate (Hoekstra and Ritsma, 1977;Moore and Glasberg, 1988;Moore and Peters, 1992;Houtsma and Smurzynski, 1990;Kaernbach and Bering, 2001;Oxenham, 2003, 2006). For tones with intermediate harmonics, with lowest harmonic in the range 8e14, the pitch may be derived either from estimates of the frequencies of partially resolved harmonics or from the temporal fine structure (TFS) of the waveform evoked on the basilar membrane by the interference of two or more harmonics (Schouten, 1940;Schouten et al, 1962;; this pitch is represented in the temporal patterns of discharge of primary auditory neurons (Javel, 1980;Moore, 1980;Delgutte, 1996a, 1996b).…”

Rapid estimation of high-parameter auditory-filter shapes

“…However, for narrower prior distributions, faster convergence rates would be expected. Third, for auditory filter shapes from very high or very low frequency regions, it may be advantageous to incorporate the effects of the middle-ear transfer function and to use maskers with upper and lower bands of unequal levels (e.g., Jurado and Moore, 2010). Or, one might wish to implement the qAF procedure so that the spectrum levels associated with the two masker bands are separately adjusted.…”

Effects of Low- and High-Frequency Side Bands of Notched Noise on Masking and Auditory Filter Shape at Very High Frequencies

“…The CMF is influenced by the changes in the spectrum of the modulated signal caused by cochlear distortions at low frequencies, by middle ear attenuation, and by the shape of the absolute threshold curve which becomes much steeper as the frequency decreases below 200 Hz (Sęk, Moore, 1994;Sęk, 1994;2000). Middle ear attenuation was widely discussed in several publications (Jurado, Moore, 2010;Shailer et al, 1990;Zhou, 1995). For example, Jurado and Moore (2010) assumed that the effects of middle ear transduction are most pronounced in the low frequency range.…”