Henry S. Cheang

The sound of sarcasm

The present study was conducted to identify possible acoustic cues of sarcasm. Native English speakers produced a variety of simple utterances to convey four different attitudes: sarcasm, humour, sincerity, and neutrality. Following validation by a separate naive group of native English speakers, the recorded speech was subjected to acoustic analyses for the following features: mean fundamental frequency (F0), F0 standard deviation, F0 range, mean amplitude, amplitude range, speech rate, harmonics-to-noise ratio (HNR, to probe for voice quality changes), and one-third octave spectral values (to probe resonance changes). The results of analyses indicated that sarcasm was reliably characterized by a number of prosodic cues, although one acoustic feature appeared particularly robust in sarcastic utterances: overall reductions in mean F0 relative to all other target attitudes. Sarcasm was also reliably distinguished from sincerity by overall reductions in HNR and in F0 standard deviation. In certain linguistic contexts, sarcasm could be differentiated from sincerity and humour through changes in resonance and reductions in both speech rate and F0 range. Results also suggested a role of language used by speakers in conveying sarcasm and sincerity. It was concluded that sarcasm in speech can be characterized by a specific pattern of prosodic cues in addition to textual cues, and that these acoustic characteristics can be influenced by language used by the speaker.

The Impact of Parkinson's Disease on Vocal-Prosodic Communication from the Perspective of Listeners.

An expressive disturbance of speech prosody has long been associated with idiopathic Parkinsons disease (PD), but little is known about the impact of dysprosody on vocal-prosodic communication from the perspective of listeners. Recordings of healthy adults (n=12) and adults with mild to moderate PD (n=21) were elicited in four speech contexts in which prosody serves a primary function in linguistic or emotive communication (phonemic stress, contrastive stress, sentence mode, and emotional prosody). Twenty independent listeners naive to the disease status of individual speakers then judged the intended meanings conveyed by prosody for tokens recorded in each condition. Findings indicated that PD speakers were less successful at communicating stress distinctions, especially words produced with contrastive stress, which were identifiable to listeners. Listeners were also significantly less able to detect intended emotional qualities of Parkinsonian speech, especially for anger and disgust. Emotional expressions that were correctly recognized by listeners were consistently rated as less intense for the PD group. Utterances produced by PD speakers were frequently characterized as sounding sad or devoid of emotion entirely (neutral). Results argue that motor limitations on the vocal apparatus in PD produce serious and early negative repercussions on communication through prosody, which diminish the social-linguistic competence of Parkinsonian adults as judged by listeners.

Acoustic markers of sarcasm in Cantonese and English

The goal of this study was to identify acoustic parameters associated with the expression of sarcasm by Cantonese speakers, and to compare the observed features to similar data on English [Cheang, H. S. and Pell, M. D. (2008). Speech Commun. 50, 366-381]. Six native Cantonese speakers produced utterances to express sarcasm, humorous irony, sincerity, and neutrality. Each utterance was analyzed to determine the mean fundamental frequency (F0), F0-range, mean amplitude, amplitude-range, speech rate, and harmonics-to-noise ratio (HNR) (to probe voice quality changes). Results showed that sarcastic utterances in Cantonese were produced with an elevated mean F0, and reductions in amplitude- and F0-range, which differentiated them most from sincere utterances. Sarcasm was also spoken with a slower speech rate and a higher HNR (i.e., less vocal noise) than the other attitudes in certain linguistic contexts. Direct Cantonese-English comparisons revealed one major distinction in the acoustic pattern for communicating sarcasm across the two languages: Cantonese speakers raised mean F0 to mark sarcasm, whereas English speakers lowered mean F0 in this context. These findings emphasize that prosody is instrumental for marking non-literal intentions in speech such as sarcasm in Cantonese as well as in other languages. However, the specific acoustic conventions for communicating sarcasm seem to vary among languages.

An acoustic investigation of Parkinsonian speech in linguistic and emotional contexts

Abstract The speech prosody of a group of patients in the early stages of Parkinsons disease (PD) was compared to that of a group of healthy age- and education-matched controls to quantify possible acoustic changes in speech production secondary to PD. Both groups produced standardized speech samples across a number of prosody conditions: phonemic stress, contrastive stress, and emotional prosody. The amplitude, fundamental frequency, and duration of all tokens were measured. PD speakers produced speech that was of lower amplitude than the tokens of healthy speakers in many conditions across all production tasks. Fundamental frequency distinguished the two speaker groups for contrastive stress and emotional prosody production, and duration differentiated the groups for phonemic stress production. It was concluded that motor impairments in PD lead to adverse and varied acoustic changes which affect a number of prosodic contrasts in speech and that these alterations appear to occur in earlier stages of disease progression than is often presumed by many investigators.

The effects of Parkinson’s disease on the production of contrastive stress

Reduced speech intelligibility has been observed clinically among patients with Parkinson’s disease (PD); one possible contributor to these problems is that motor limitations in PD reduce the ability to mark linguistic contrasts in speech using prosodic cues. This study compared acoustic aspects of the production of contrastive stress (CS) in sentences that were elicited from ten subjects with PD and ten matched control subjects without neurological impairment. Subjects responded to questions that biased them to put emphasis on the first, middle, or last word of target utterances. The mean vowel duration and mean fundamental frequency (F0) of each keyword were then measured, normalized, and analyzed for possible differences in the acoustic cues provided by each group to signal emphatic stress. Both groups demonstrated systematic differences in vowel lengthening between emphasized and unemphasized words across word positions; however, controls were more reliable than PD subjects at modulating the F0 of emp...