title: Channel selection in the modulation domain for improved speech intelligibility in noise.
abstract: Background noise reduces the depth of the low-frequency envelope modulations known to be important for speech intelligibility. The relative strength of the target and masker envelope modulations can be quantified using a modulation signal-to-noise ratio, (S/N)(mod), measure. Such a measure can be used in noise-suppression algorithms to extract target-relevant modulations from the corrupted (target + masker) envelopes for potential improvement in speech intelligibility. In the present study, envelopes are decomposed in the modulation spectral domain into a number of channels spanning the range of 0-30 Hz. Target-dominant modulations are identified and retained in each channel based on the (S/N)(mod) selection criterion, while modulations which potentially interfere with perception of the target (i.e., those dominated by the masker) are discarded. The impact of modulation-selective processing on the speech-reception threshold for sentences in noise is assessed with normal-hearing listeners. Results indicate that the intelligibility of noise-masked speech can be improved by as much as 13 dB when preserving target-dominant modulations, present up to a modulation frequency of 18 Hz, while discarding masker-dominant modulations from the mixture envelopes.
authors.affiliation: Department of Electrical Engineering, University of Texas at Dallas, Richardson, Texas 75083-0688, USA.
authors.forename: Kamil K
authors.initials: KK
authors.lastname: Wójcicki
authors.forename: Philipos C
authors.initials: PC
authors.lastname: Loizou
mesh_terms: D000465:Algorithms; D005260:Female; D006801:Humans; D008297:Male; D009622:Noise; D010470:Perceptual Masking / Q000502:physiology*; D059629:Signal-To-Noise Ratio; D013018:Sound Spectrography; D013061:Speech Acoustics; D013065:Speech Intelligibility / Q000502:physiology*