James D. Harnsberger

Noise and tremor in the perception of vocal aging in males.

OBJECTIVE/HYPOTHESIS To specify a set of acoustic cues for vocal aging and to establish their perceptual relevance. STUDY DESIGN Perceptual testing. METHODS To identify the acoustic and perceptual correlates of the aging voice, voice quality [in conjunction with speaking rate and fundamental frequency (F(0))] was systematically manipulated using resynthesis to determine its effect on perceived age. Ten young male voices were resynthesized using two levels of noise (random modulation of F(0) contour) and two levels of tremor (constant modulation of F(0) contour with a low-amplitude wave) under a speaking-rate manipulation (an increase in speaking rate that is common to older male voices). These materials were submitted to 40 naive listeners in an age-estimation task. Two sets of comparison materials were also included for evaluation: unmanipulated samples from a 150 voice database of young, middle-aged, and older voices and disordered voice samples representing natural manifestations of the voice qualities of interest. RESULTS Speaking rate, highest degree of tremor, and highest degree of noise all shifted, in an additive manner, the mean perceived age of the young male voices by a maximum of 12 years on average; individual voices were observed being shifted by a generation. Fundamental frequency manipulations had no significant effect on perceived age. CONCLUSIONS Voice quality (both tremor and noise) and speaking rate are all perceptually relevant cues of age in male voices.

A cross-language study of the identification of non-native nasal consonants varying in place of articulation

Seven listener groups, varying in terms of the nasal consonant inventory of their native language, orthographically labeled and rated a set of naturally produced non-native nasal consonants varying in place of articulation. The seven listener groups included speakers of Malayalam, Marathi, Punjabi, Tamil, Oriya, Bengali, and American English. The stimulus set included bilabial, dental, alveolar, and retroflex nasals from Malayalam, Marathi, and Oriya. The stimulus set and nasal consonant inventories of the seven listener groups were described by both phonemic and allophonic representations. The study was designed to determine the extent to which phonemic and allophonic representations of perceptual categories can be used to predict a listener groups identification of non-native sounds. The results of the experiment showed that allophonic representations were more successful in predicting the native category that listeners used to label a non-native sound in a majority of trials. However, both representations frequently failed to accurately predict the goodness of fit between a non-native sound and a perceptual category. The results demonstrate that the labeling and rating of non-native stimuli were conditioned by a degree of language-specific phonetic detail that corresponds to perceptually relevant cues to native language contrasts.

Effects of Quantitative Linguistic Feedback to Caregivers of Young Children A Pilot Study in China

Changes in natural language environments of families receiving quantitative language feedback in Shanghai were investigated. Volunteer parents of 22 children aged 5 to 30 months were recruited from a hospital and a learning center. Quantitative measures of adult word count and conversational turns with children were collected regularly over 6 months. Feedback reports to caregivers included individual family plus group counts. Impact was assessed by changes in quantitative measures and pre–post child language assessments. Overall, families increased word/turn counts significantly during the first 3 months and then regressed to baseline levels. However, parents whose word count output was below median at baseline significantly increased word count output to study conclusion. Adult word and turn counts were related to a subset of language development measures. Quantitative feedback with parent training had a significant impact on adult–child interactions, particularly for below-median families. Larger studies of wider socioeconomic status with control groups are needed.

Evaluating Language Environment Analysis System Performance for Chinese: A Pilot Study in Shanghai

PURPOSE The purpose of this study was to evaluate performance of the Language Environment Analysis (LENA) automated language-analysis system for the Chinese Shanghai dialect and Mandarin (SDM) languages. METHOD Volunteer parents of 22 children aged 3-23 months were recruited in Shanghai. Families provided daylong in-home audio recordings using LENA. A native speaker listened to 15 min of randomly selected audio samples per family to label speaker regions and provide Chinese character and SDM word counts for adult speakers. LENA segment labeling and counts were compared with rater-based values. RESULTS LENA demonstrated good sensitivity in identifying adult and child; this sensitivity was comparable to that of American English validation samples. Precision was strong for adults but less so for children. LENA adult word count correlated strongly with both Chinese characters and SDM word counts. LENA conversational turn counts correlated similarly with rater-based counts after the exclusion of three unusual samples. Performance related to some degree to child age. CONCLUSIONS LENA adult word count and conversational turn provided reasonably accurate estimates for SDM over the age range tested. Theoretical and practical considerations regarding LENA performance in non-English languages are discussed. Despite the pilot nature and other limitations of the study, results are promising for broader cross-linguistic applications.

Perceiving the effects of ethanol intoxication on voice.

Many conditions operate to degrade the quality of the human voice. Alcohol intoxication is one of them. In this project, the objectives were to examine the ability of human listeners to accurately estimate both the presence and severity of intoxication from two types of speech samples. A review of available data suggests that, although listeners can often identify individuals who are intoxicated simply by hearing samples of their voice, they are less efficient at accurately determining the severity of this condition. A number of aural-perceptual studies were carried out to test these relationships. Populations of speakers, selected based on rigorous criteria, provided orally read and extemporaneous utterances when sober and at three highly controlled levels of intoxication. Listener groups of university students and professionals attempted to identify both the existence and specific level of intoxication present. It was found that these individuals were proficient in recognizing the presence of, and increases in, intoxication but were less accurate in gauging the specific levels. Several subordinate relationships were also investigated. In this regard, statistically significant differences were not found between male and female listeners or between professionals and lay listeners; however, they were found for different classes of speech. That is, it was shown that text difficulty correlated with severity of effect.

Pitch range and focus in Hindi.

A study of intonation in Hindi included sentences, read by six native speakers, in which different individual words were emphasized or focused. Hindi resembles some other languages (English, Bengali, Korean) in marking a focused constituent prosodically by reducing the normal prominence given to neighboring constituents. In Bengali and English, all constituents preceding a focused word are deaccented, failing to show typical contours [Hayes and Lahiri, Nat. Lang. Ling. Theory 9, 47–96 (1991)]. The reverse occurs in Korean, with following constituents being deaccented (Jun 1993, dissertation). In Hindi, deaccenting of following constituents is also observed; however, the phenomenon is characterized by a dramatic compression of the speaker’s pitch range following the focus word. For narrow pitch ranges, compression effects on F0 realization are equivalent to those of deaccenting. For wider ranges, following constituents show the typical rising contours over content words found in declarative utterances with...

Issues in forensic voice.

The following article provides a general review of an area that can be referred to as Forensic Voice. Its goals will be outlined and that discussion will be followed by a description of its major elements. Considered are (1) the processing and analysis of spoken utterances, (2) distorted speech, (3) enhancement of speech intelligibility (re: surveillance and other recordings), (4) transcripts, (5) authentication of recordings, (6) speaker identification, and (7) the detection of deception, intoxication, and emotions in speech. Stress in speech and the psychological stress evaluation systems (that some individuals attempt to use as lie detectors) also will be considered. Points of entry will be suggested for individuals with the kinds of backgrounds possessed by professionals already working in the voice area.

Speaker identification: The case for speech vector analysis.

The problem of identifying speakers from voice analysis is a serious one. Many analytical procedures have been proposed; most have been based on signal analysis algorithms. Yet it is clear that human perceivers can make accurate identifications (even under difficult circumstances), and extensive research supports this position. How do they accomplish this task? They do so by acoustic and temporal assessment of the talker’s speech/voice signal. Several analysis procedures have attempted to mimic human perception for this purpose, and a brief review of the relevant data will be presented. It will be followed by a presentation of the results of a four‐vector experiment in which each vector integrates 3–5 speech parameters. Identification of 28 male voices resulted from three replications in a field of 10 foil voices. It was found that identification scores for the voice, vowel, and fundamental frequency vectors were high, and that for the temporal vector was modest. Moreover, of the summation scores across a...

The application of a psychophysical difference metric to perceptual similarity judgments in vowels

Models of cross‐language speech perception have had limited success in predicting the discriminability or perceptual similarity of non‐native contrasts. These failures may be attributed partly to an inability to quantify the phonetic differences between non‐native speech sounds. This study attempted to quantify such gross psychophysical differences between speech sounds, specifically by utilizing dynamic time warping (DTW) on human factor cepstral coefficients to compare the spectrum of the entire length of the speech sounds in question. This technique has been successfully applied to account for the discriminability of different non‐native consonant contrasts [Harnsberger, J. D., Shrivastav, R., and Skowronski, M.; J. Acous. Soc. Am. 117, 2460, 2005]. This study extends this work to perceptual similarity judgments of vowels. Specifically, twenty native speakers of English were presented with all possible pairings of ten vowels produced by two speakers of English. Subjects were asked to rate their similarity on a seven point scale. The resulting similarity scores were then compared with the output matrix of the DTW psychophysical difference metric for the same stimulus materials. The results showed a significant correlation (r=.60**) between the two measures, demonstrating the efficacy of the metric with a greater range of stimulus types and tasks.

Shifting perceptions of age in voice

A series of experiments have been carried out in order to identify the acoustical and perceptual correlates of the aging voice. The initial phase of the program was to identify those voice parameters which signal a person’s age; the second phase was to systematically shift these parameters in order to determine if a parallel change in perceived age would occur. This second study focused on temporal characteristics related to voice. In this instance, standard speech samples for 16 males aged 70–90 years were contrasted with those of 14 males aged 20–33 years. The features studied included the following: (1) sentence duration, (2) word duration, (3) diphthong duration, (4) consonant‐vowel ratios, (5) number of pauses and (6) pause duration. Significant differences were found for all relationships. Subsequently, a preliminary study was carried out where the voices were synthesized and the temporal parameters for the two groups shifted toward each other. The preliminary data suggest that such modifications lead especially to the idea that the voices of older individuals actually were those of younger men.