title: The effect of spatial separation in distance on the intelligibility of speech in rooms.
abstract: The influence of spatial separation in source distance on speech reception thresholds (SRTs) is investigated. In one scenario, the target was presented at 0.5 m distance, and the masker varied from 0.5 m distance up to 10 m. In a second scenario, the masker was presented at 0.5 m distance and the target distance varied. The stimuli were synthesized using convolution with binaural room impulse responses (BRIRs) measured on a dummy head in a reverberant auditorium, and were equalized to compensate for distance-dependent spectral and intensity changes. All sources were simulated directly in front of the listener. SRTs decreased monotonically when the target was at 0.5 m and the speech-masker was moved further away, resulting in a SRT improvement of up to 10 dB. When the speech masker was at 0.5 m and the target was moved away, a large variation across subjects was observed. Neither short-term signal-to-noise ratio (SNR) improvements nor cross-ear glimpsing could account for the observed improvement in intelligibility. However, the effect might be explained by an improvement in the SNR in the modulation domain and a decrease in informational masking. This study demonstrates that distance-related cues can play a significant role when listening in complex environments.
authors.affiliation: National Acoustic Laboratories, Australian Hearing, 16 University Avenue, Macquarie University, New South Wales 2109, Australia.
authors.forename: Adam
authors.initials: A
authors.lastname: Westermann
authors.affiliation: National Acoustic Laboratories, Australian Hearing, 16 University Avenue, Macquarie University, New South Wales 2109, Australia.
authors.forename: Jörg M
authors.initials: JM
authors.lastname: Buchholz
mesh_terms: D000161:Acoustic Stimulation; D000328:Adult; D001301:Audiometry, Pure-Tone; D001309:Auditory Threshold; D003463:Cues; D005160:Facility Design and Construction; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009622:Noise / Q000009:adverse effects*; D010470:Perceptual Masking; D059629:Signal-To-Noise Ratio; D013017:Sound Localization; D013065:Speech Intelligibility; D013067:Speech Perception; D013069:Speech Reception Threshold Test; D055815:Young Adult