title: Intelligibility of time-compressed speech: the effect of uniform versus non-uniform time-compression algorithms.
abstract: For assessing hearing aid algorithms, a method is sought to shift the threshold of a speech-in-noise test to (mostly positive) signal-to-noise ratios (SNRs) that allow discrimination across algorithmic settings and are most relevant for hearing-impaired listeners in daily life. Hence, time-compressed speech with higher speech rates was evaluated to parametrically increase the difficulty of the test while preserving most of the relevant acoustical speech cues. A uniform and a non-uniform algorithm were used to compress the sentences of the German Oldenburg Sentence Test at different speech rates. In comparison, the non-uniform algorithm exhibited greater deviations from the targeted time compression, as well as greater changes of the phoneme duration, spectra, and modulation spectra. Speech intelligibility for fast Oldenburg sentences in background noise at different SNRs was determined with 48 normal-hearing listeners. The results confirmed decreasing intelligibility with increasing speech rate. Speech had to be compressed to more than 30% of its original length to reach 50% intelligibility at positive SNRs. Characteristics influencing the discrimination ability of the test for assessing effective SNR changes were investigated. Subjective and objective measures indicated a clear advantage of the uniform algorithm in comparison to the non-uniform algorithm for the application in speech-in-noise tests.
authors.affiliation: Institute of Hearing Technology and Audiology, Jade University of Applied Sciences, Ofener Straße 16/19, D-26121 Oldenburg, Germany.
authors.forename: Anne
authors.initials: A
authors.lastname: Schlueter
authors.affiliation: Phonak AG, Science and Technology, Laubisrütistrasse 28, CH-8712 Stäfa, Switzerland.
authors.forename: Ulrike
authors.initials: U
authors.lastname: Lemke
authors.affiliation: Medical Physics, Institute of Physics, Carl-von-Ossietzky University Oldenburg, D-26111 Oldenburg, Germany.
authors.forename: Birger
authors.initials: B
authors.lastname: Kollmeier
authors.affiliation: Institute of Hearing Technology and Audiology, Jade University of Applied Sciences, Ofener Straße 16/19, D-26121 Oldenburg, Germany.
authors.forename: Inga
authors.initials: I
authors.lastname: Holube
mesh_terms: D000161:Acoustic Stimulation; D000328:Adult; D000465:Algorithms; D001302:Audiometry, Speech; D001309:Auditory Threshold; D003463:Cues; D004192:Discrimination, Psychological; D005260:Female; D006310:Hearing Aids; D006801:Humans; D008297:Male; D009622:Noise / Q000009:adverse effects; D010470:Perceptual Masking; D010700:Phonetics; D012815:Signal Processing, Computer-Assisted; D013061:Speech Acoustics; D013065:Speech Intelligibility; D013997:Time Factors; D014833:Voice Quality; D055815:Young Adult