Speech perception models decompose subband signals into acoustic and modulation envelopes

Evidence

The subband power P, in dB, was calculated using 22 fourth-order gammatone filters with equivalent rectangular bandwidths. The center frequencies were spaced on a third-octave grid, covering a range from 63 Hz to 8 kHz. The Hilbert envelope of each filter output was extracted and low-pass filtered using a first-order Butterworth filter with a cut-off frequency of 150 Hz. The envelopes were down-sampled to a sampling rate of 1050 Hz. The modulation power Pmod , in dB, was obtained using the subband envelope extraction described above, followed by a modulation filterbank consisting of 3 second-order band-pass filters (center frequencies of 4, 8, and 16 Hz) in parallel with one third-order low-pass filter (cut-off frequency of 2 Hz). — Dijk, Pim van, Physiology, Psychoacoustics and…, 5602

The subband power P, in dB, was calculated using 22 fourth-order gammatone filters with equivalent rectangular bandwidths. The center frequencies were spaced on a third-octave grid, covering a range from 63 Hz to 8 kHz. The Hilbert envelope of each filter output was extracted and low-pass filtered using a first-order Butterworth filter with a cut-off frequency of 150 Hz. The envelopes were down-sampled to a sampling rate of 1050 Hz. — Dijk, Pim van, Physiology, Psychoacoustics and…, 5604

Categorization

• DEFINE: Gives concrete parameters of energy- vs modulation-based representations (gammatone filters, modulation bandwidths 4-16 Hz) — useful reference detail.
• corroborated: 2 independent passages support this claim — Dijk, Pim van, Physiology, Psychoacoustics and…, 5602; Dijk, Pim van, Physiology, Psychoacoustics and…, 5604