Auditory chimera technique swaps envelope and fine structure across frequency channels

Evidence

The tone tokens in which the durations of the four tones in each monosyllable were within a 5-ms precision were chosen as the original tone tokens. These tone tokens were processed through a 16-channel chimerizer in which the FS and E of any two different tone tokens of the same syllable were swapped. For example, two tokens of the same syllable but with different tone patterns were passed through 16 band-pass filters to split each sound into 16 channels. The output of each filter was then divided into its E and FS using a Hilbert transform. — Dijk, Pim van, Physiology, Psychoacoustics and…, 3380

Experiment I was aimed to investigate the ability of lexical tone perception for both SNHL and ANSD listeners, and to assess the relative contributions of FS and E to their lexical tone perception using the “auditory chimera” technique (Smith et al. 2002 ; Xu and Pfingst 2003 ). As described in Wang et al. ( 2011 ), the chimeric tokens were generated in a condition with 16 channels. These 16 FIR band-pass filters with nearly rectangular response were equally spaced on a cochlear frequency map, ranging from 80 to 8820 Hz. In order to avoid the blurriness between E and FS in the chimeric stimuli, we adopted a lowpass filter (cut-off at 64 Hz) for extraction of the envelopes from the filters. — Dijk, Pim van, Physiology, Psychoacoustics and…, 3384

Categorization

• DEFINE: Explains the auditory chimera technique and its Hilbert-transform-based envelope/fine-structure split — a core method for separating the two cues.
• corroborated: 2 independent passages support this claim — Dijk, Pim van, Physiology, Psychoacoustics and…, 3380; Dijk, Pim van, Physiology, Psychoacoustics and…, 3384