Effects of Cooperating and Conflicting Cues on Speech Intonation Recognition by Cochlear Implant Users and Normal Hearing Listeners

Abstract

Cochlear implant (CI) recipients have only limited access to fundamental frequency (F0) information, and thus exhibit deficits in speech intonation recognition. For speech intonation, F0 serves as the primary cue, and other potential acoustic cues (e.g. intensity properties) may also contribute. This study examined the effects of cooperating or conflicting acoustic cues on speech intonation recognition by adult CI and normal hearing (NH) listeners with full-spectrum and spectrally degraded speech stimuli. Identification of speech intonation that signifies question and statement contrasts was measured in 13 CI recipients and 4 NH listeners, using resynthesized bi-syllabic words, where F0 and intensity properties were systematically manipulated. The stimulus set was comprised of tokens whose acoustic cues (i.e. F0 contour and intensity patterns) were either cooperating or conflicting. Subjects identified if each stimulus is a ‘statement’ or a ‘question’ in a single-interval, 2-alternative forced-choice (2AFC) paradigm. Logistic models were fitted to the data, and estimated coefficients were compared under cooperating and conflicting conditions, between the subject groups (CI vs. NH), and under full-spectrum and spectrally degraded conditions for NH listeners. The results indicated that CI listeners’ intonation recognition was enhanced by cooperating F0 contour and intensity cues, but was adversely affected by these cues being conflicting. On the other hand, with full-spectrum stimuli, NH listeners’ intonation recognition was not affected by cues being cooperating or conflicting. The effects of cues being cooperating or conflicting were comparable between the CI group and NH listeners with spectrally degraded stimuli. These findings suggest the importance of taking multiple acoustic sources for speech recognition into consideration in aural rehabilitation for CI recipients.

Gender Categorization Is Abnormal in Cochlear Implant Users

“…To quantify the contribution of the F0 and VTL, a simpler logistic regression model was used (as described, for instance, by Peng et al 2009). The "perceptual weights" for each cue were estimated as the coefficients for the f0 and vtl factors in the logistic regression model.…”

Recognition of interrupted sentences under conditions of spectral degradation

“…With 16-24 spectral channels and a 400 Hz envelope filter cutoff, sufficient F0 information is present in the speech signal to allow for good performance in tasks such as gender recognition and F0-based intonation recognition (e.g., Fu et al, 2004;Gonzalez and Oliver, 2005;Chatterjee and Peng, 2008;Peng et al, 2009). Thus, if the F0 contour is important in the process of reconstructing interrupted speech, we would minimally expect it to help in the perception of 16-channel, 24-channel, and full-spectrum speech and to some extent with 8-channel speech.…”

“…Noise-band vocoding methods were similar to those used by Shannon et al (1995). The lowpass filter cutoff for temporal envelope extraction was 400 Hz ͑24 dB/ oct͒ to preserve usable F0-based intonation cues from the male talker (Chatterjee and Peng, 2008;Peng et al, 2009). Signal gating was applied (using MATLAB) to the NBV sentences (50% duty cycle, 100 ms on, 100 ms off, or 5 Hz gating, and 10 ms cosine-tapered rise/fall times).…”

Low-frequency fine-structure cues allow for the online use of lexical stress during spoken-word recognition in spectrally degraded speech

“…Also, the perception of prosody is generally poorer in CI users compared to normalhearing listeners (e.g., Holt and McDermott, 2013;Holt et al, 2016;Marx et al, 2015;Meister et al, 2009Meister et al, , 2011Morris et al, 2013;Peng et al, 2008Peng et al, , 2009. Although the temporal envelope of speech carries information related to duration, pauses, and amplitude, the reduced spectral and temporal resolution in CI listening (e.g., Oxenham and Kreft, 2014) negatively impact the perception of prosody.…”