Adult Talkers Research Articles

Impact of talker variability on language development in two-year-olds.

This research investigated the impact of the number of talkers with whom children engage in daily conversation on their language development. Two surveys were conducted in 2020, targeting two-year-olds growing up in Japanese monolingual families. Caregivers reported the number of talkers in three age groups and children's productive vocabulary via questionnaires. The results demonstrated significant effects of variability in talkers in fifth grade or above in Study 1 (N = 50; male = 23; r = .372) and in adult talkers in Study 2 (N = 175; non-nursery going; male = 76; r = .184) on children's vocabulary development, after controlling for language exposure time and demographic variables. Possible mediating factors are discussed. This research extends previous findings from immigrant bilingual children to monolingual speakers in Japan, suggesting the potential contribution of available talkers other than caregivers in conversational environments.

Stories and words online regional dialect corpus collection

Online data collection allows for access to diverse populations. In the current study, we used online recruitment and data collection methods to obtain a corpus of read short stories, real English words, and nonwords from adult talkers representing three authentic regional dialects of American English and one novel accent. The authentic dialects are New England, Northern, and Southern American English and are each represented by 8–10 talkers, ranging in age from 22 to 75 years old. The novel accent was produced by five Spanish-English bilinguals with training in linguistics, who were asked to produce Spanish /o/ in an otherwise English segmental context. The four target varieties each contain one vowel pair of interest, in which the vowels within the pair are relatively more ambiguous than in the other varieties. Each talker produced one familiar short story (e.g., Goldilocks and the Three Bears) with 40 tokens of each vowel within the target pair for their dialect, as well as a set of real words and nonwords that represent both the target vowel pair for their dialect and the other three vowel pairs for comparison across dialects. All corpus materials are available to the scholarly community.

Proprioceptive Acuity Influences Speech Motor Control in Healthy Adult Talkers.

Somatosensory feedback, including proprioception, is important for speech production. This study evaluates proprioceptive acuity of the tongue using a position-matching task and determining if proprioceptive acuity impacts speech motor control in healthy adult talkers. Twenty-five young adults with no history of speech, language, or hearing disorders had their tongue movements recorded with an electromagnetic articulograph while completing a position-matching task. Participants were also asked to repeat two sentences that differed in the somatosensory feedback obtained. One sentence provided both tactile and proprioceptive feedback, whereas the other primarily provided proprioceptive feedback. Participants ranged in proprioceptive acuity as measured by the position-matching task. Talkers with smaller position-matching errors and, therefore, higher proprioceptive acuity had smaller movements and slower speeds for both sentences. Talkers with lower proprioceptive acuity had reduced speech movement stability for the sentence that primarily provides proprioceptive feedback. Proprioceptive acuity of the tongue can be evaluated using a position-matching task, and acuity is associated with more efficient speech movements and greater speech movement stability, particularly when producing utterances that provide less tactile feedback. https://doi.org/10.23641/asha.24293740.

Using a novel in-mask non-invasive ventilator microphone to improve talker intelligibility in healthy and hospitalised adults

Purpose: Non-invasive ventilation (NIV) provides respiratory support without invasive endotracheal intubation but can hinder patients’ ability to communicate effectively. The current study presents preliminary results using a novel in-mask ventilator microphone to enhance talker intelligibility while receiving NIV. Method: A proof-of-concept study assessed sentence intelligibility of five healthy adult talkers using a prototype model of the microphone under continuous positive airway pressure (CPAP; 5/5 cm H2O) and bilevel positive airway pressure (BiPAP; 8/4 cm H2O) ventilator conditions. A pilot study then assessed intelligibility, subjective comprehensibility and naturalness, and patient- and conversation partner-reported communication outcomes for eight patients undergoing therapeutic NIV while being treated in an intensive care unit (ICU). Result: Intelligibility increased significantly with the microphone on in the BiPAP condition for healthy volunteers. For patients undergoing NIV in an ICU, intelligibility, comprehensibility, and patient and conversation partner ratings of conversation satisfaction significantly improved with the microphone on. Patients with lower baselines without the microphone in certain measures (intelligibility, comprehensibility) generally showed a greater microphone benefit than patients with higher baselines. Conclusion: Use of a novel microphone integrated into NIV improved intelligibility during ventilation for both healthy volunteers and patients undergoing therapeutic NIV. Additional clinical studies will define precise benefits and implications of such improved intelligibility.

Normalization of speech kinematic data for characterizing primary muscle tension dysphonia

Primary muscle tension dysphonia (pMTD) is a voice disorder of unknown etiology in which people have reduced volume and become easily fatigued. The tongue has biomechanical linkage to the laryngeal motor system that affects the voice, suggesting that tongue movement variability might be a marker for this disorder. Previous studies of healthy/disordered speech have reduced individual talker differences in physical vocal tract characteristics via normalization procedures. Here, we obtained tongue movement data for diadochokinetic sequences produced by healthy adult talkers and people with pMTD. We used an electromagnetic articulography system to test three healthy adult talkers and a participant with pMTD. We recorded vertical displacement of the tongue dorsum for sustained /a/ and 30 sec of rapidly repeated /pataka/. Displacement (mm) was scaled relative to each talker’s sustained vowel production, while movement time (msec) was normalized by dividing each /ka/ portion by the corresponding /pataka/ utterance length. The results suggest (1) normalization effectively reduced talker variability in tongue movement displacement and timing, and (2) the talker with pMTD showed markedly higher temporal variability, compared to the control talkers. We are currently testing this putative group difference using additional participants.

How sociolinguistic factors shape children's subjective impressions of teacher quality.

When university students are asked to rate their instructors, their evaluations are often influenced by the demographic characteristics of the instructor-such as the instructor's race, gender, or language background. These influences can manifest in unfair systematic biases against particular groups of teachers and hamper movements to promote diversity in higher education. When and how do these biases develop? Here, we begin to address these questions by examining children's sociolinguistic biases against teachers who speak with different accents. To do this, we presented 5-year-old Canadian English-speaking children with pairs of adult talkers. Children were asked to select "who they'd like to be their teacher" then they rated "how good of a teacher" they thought each talker would be on a 5-point scale. In each trial, one talker spoke in the locally dominant variety of Canadian English, and the other spoke in a different accent. Children strongly preferred Canadian-accented teachers over teachers who spoke with non-native (i.e., French or Dutch) accents, but also demonstrated a preference for Canadian teachers over teachers who spoke with non-local regional accents (i.e., Australian or British). In line with the binary choice data, children rated the Canadian talkers more favourably. The relationship between the gender of the teacher and the gender of the child also impacted ratings. This work demonstrates that even at the onset of formal education, children may already exhibit signs of accent-based biases. We discuss these findings in relation to the growing literature on implicit bias in higher education.

Children’s perception of accent distance for native and nonnative varieties

Adults are sensitive to the presence and strength of accents different from their own. Children also are sensitive to the presence of unfamiliar accents, but much less is known about their awareness of accent strength. To address this gap, this study used a ladder task, in which listeners rank talkers based on their perceived distance from the home standard. Female adult talkers representing four native, six nonnative, and one bilingual English accents were included. Six-year-olds, 12-year-olds, and adults completed two ladders in which all talkers produced the same sentence and one ladder with a unique sentence for each talker. Average rankings were significantly correlated across age groups, with greater agreement for consistent than unique sentence ladders. Strategies used by six-year-olds differed from older children and adults. The youngest children arranged talkers into two or three distinct groups with more horizontal groupings while older children and adults primarily arranged talkers in a vertical array. These results support previous findings that young children distinguish their own accent from unfamiliar accents. Furthermore, the study provides new data demonstrating that sensitivity to accent distance emerges in the early school-aged years with continued maturation during middle childhood. [Work by NSF grants 1941691 and 1941662.]

Intelligibility of Noise-Adapted and Clear Speech in Energetic and Informational Maskers for Native and Nonnative Listeners.

This study explored clear speech (CS) and noise-adapted speech (NAS) intelligibility benefits for native and nonnative English listeners. It also examined how the two speaking style adaptations interact with maskers that vary from purely energetic to largely informational at different signal-to-noise ratios (SNRs). Materials consisted of 40 sentences produced by 10 young adult talkers in a conversational and a clear speaking style under two conditions: (a) in quiet and (b) in response to speech-shaped noise (SSN) played over headphones (NAS). Young adult native (Experiment 1) and nonnative (Experiment 2) English listeners heard target sentences presented in two-talker (2T) babble, six-talker (6T) babble, or SSN and at an "easier" and a "harder" SNR. When talkers produced CS and NAS, word recognition accuracy was significantly improved for both listener groups. The largest intelligibility benefit was obtained for the CS produced in response to noise (CS+NAS). Overall accuracy was highest in 2T babble. Accuracy was higher in SSN than in 6T babble for nonnative listeners at both levels of listening difficulty but only at a more difficult SNR for native listeners. Listeners benefited from CS and NAS most in the presence of SSN and least in 2T babble. When SNRs were the same for the two listener groups, native listeners outperformed nonnative listeners in almost all listening conditions, but nonnative listeners benefited more from CS and NAS in 6T babble than native listeners did. Combined speaking style enhancements, CS+NAS, provided the largest intelligibility increases for native and nonnative listeners in all listening conditions. The results add to the body of evidence supporting speech-oriented, behavioral therapy techniques for maximizing speech intelligibility in everyday listening situations.

Accuracy of the Language Environment Analysis (LENA) speech processing system in identifying communicative vocalizations of young children and adults

The Language Environment Analysis (LENA) system is an automated audio processing system widely used for characterizing language behaviors of children and adults for clinical and basic research. While a number of studies have assessed LENA’s reliability, its accuracy at identifying and counting speech communicative events is still not well-characterized under a range of naturalistic conditions. In two studies, we examined accuracy of LENA's speech vocalization classifications, relative to human gold standard coding for audio events, as well as word and speech vocalization counts for adults and child utterances, respectively. We found that the weighted average of accurate classification of 100-msec frames by LENA for child speech, adult female speech, and adult male speech was 57%, 61%, and 57%, respectively. Further, an analysis of LENA’s ability to accurately discriminate frames of speech vocalizations from a “key child”—a child wearing the LENA device—from speech vocalizations of other child and adult talkers and sound sources showed that LENA correctly detected key child speech vocalization frames only 41% of the time. We are currently extending this research to examine the accuracy of LENA’s child vocalization count (CVC) and conversational turn count (CTC) measures.

Bottom-up and top-down effects on the perception of children's speech

This study examined adult’s perception of spoken words produced by children and by other adults in audio-only (AO) and audiovisual (AV) contexts, to determine whether talker age affects the magnitude of AV benefit. One-syllable words produced by five 4-6 year old child talkers and five adult talkers were presented to 151 adult listeners at three signal-to-noise ratios. The SNRs were determined through pilot testing to be the ones at which adult and child talkers’ productions were recognized equally accurately in the AO condition. The magnitude of AV benefit was statistically equivalent for the adult and child talkers. However, lexical factors affected the perception of children and adults’ speech differently. Word frequency had a larger effect on the perception of children’s speech, perhaps reflecting listeners’ expectation that children would be especially unlikely to use a low frequency word. Lexical factors also affected the nature of listener errors: listeners were less likely to provide a low-frequency word when misperceiving a child than when misperceiving an adult. Listeners were also more likely to guess a word with a different CV structure than the target for children than for adults. Results suggest that listeners apply qualitatively different expectations when listening to adults and children.

Estimating the reduced benefit of infant-directed speech in cochlear implant-related speech processing

Caregivers modify their speech when talking to infants, a specific type of speech known as infant-directed speech (IDS). This speaking style facilitates language learning compared to adult-directed speech (ADS) in infants with normal hearing (NH). While infants with NH and those with cochlear implants (CIs) prefer listening to IDS over ADS, it is yet unknown how CI processing may affect the acoustic distinctiveness between ADS and IDS, as well as the degree of intelligibility of these. This study analyzed speech of seven female adult talkers to model the effects of simulated CI processing on (1) acoustic distinctiveness between ADS and IDS, (2) estimates of intelligibility of caregivers’ speech in ADS and IDS, and (3) individual differences in caregivers’ ADS-to-IDS modification and estimated speech intelligibility. Results suggest that CI processing is substantially detrimental to the acoustic distinctiveness between ADS and IDS, as well as to the intelligibility benefit derived from ADS-to-IDS modifications. Moreover, the observed variability across individual talkers in acoustic implementation of ADS-to-IDS modification and the estimated speech intelligibility was significantly reduced due to CI processing. The findings are discussed in the context of the link between IDS and language learning in infants with CIs.

The Effects of Clear Speech on American English Listener Perception of Spanish-Accented and Native English Speech

Purpose The purpose of this study was to explore (a) the effect of clear speech on intelligibility, ease of understanding, and accentedness in Spanish-accented and native English speakers of American English and (b) the extent to which accentedness predicts intelligibility and ease of understanding. Method Ten adult talkers, five native English speakers and five native Spanish speakers, read aloud 28 short sentences in habitual speech and clear speech. One hundred monolingual English listeners transcribed what they heard and rated ease of understanding using a 10-cm visual analog scale while hearing the sentences in six-talker babble. Then, accentedness (using a visual analog scale) was judged in quiet. Intelligibility was calculated as the number of words transcribed correctly for each sentence. Ten listeners with significant exposure to Spanish-accented speech rated each talker. Each listener heard only one talker, rating half the sentences in clear speech and half in habitual speech, so that no listener heard a sentence more than once for the intelligibility and ease of understanding assessments. Results Clear speech improved intelligibility and ease of understanding for both language groups, with greater improvement in nonnative talkers. Clear speech did not alter accentedness in nonnative talkers but did increase accentedness in native talkers. Accentedness did not strongly predict intelligibility but did predict ease of understanding, although the relationship was nonlinear. Conclusions Listeners who are experienced in hearing Spanish-accented speech derive significant benefits from clear speech. The difference in the predictability of accentedness for intelligibility and ease of understanding contributes further evidence to the difference in underlying cognitive processes for these two variables.

Identifying children's voices

Human adults rely on both acoustic and linguistic information to identify adult talkers. Assuming favorable conditions, adult listeners recognize other adults fairly accurately and quickly. But how well can adult listeners recognize child talkers, whose speech productions often differ dramatically from adult speech productions? Although adult talker recognition has been heavily studied, only one study to date has directly compared the recognition of unfamiliar adult and child talkers [Creel and Jimenez (2012). J. Exp. Child Psychol. 113(4), 487-509]. Therefore, the current study revisits this question with a much larger and younger sample of child talkers (N = 20); performance with adult talkers (N = 20) was also tested to provide a baseline. In Experiment 1, adults successfully distinguished between adult talkers in an AX discrimination task but performed much worse with child talkers. In Experiment 2, adults were slower and less accurate at learning to identify child talkers than adult talkers in a training-identification task. Finally, in Experiment 3, adults failed to improve at identifying child talkers after three days of training with numerous child voices. Taken together, these findings reveal a sizable difference in adults' ability to recognize child versus adult talkers. Possible explanations and implications for understanding human talker recognition are discussed.

Circumspection in using automated measures: Talker gender and addressee affect error rates for adult speech detection in the Language ENvironment Analysis (LENA) system.

Automatic speech processing devices have become popular for quantifying amounts of ambient language input to children in their home environments. We assessed error rates for language input estimates for the Language ENvironment Analysis (LENA) audio processing system, asking whether error rates differed as a function of adult talkers' gender and whether they were speaking to children or adults. Audio was sampled from within LENA recordings from 23 families with children aged 4-34 months. Human coders identified vocalizations by adults and children, counted intelligible words, and determined whether adults' speech was addressed to children or adults. LENA's classification accuracy was assessed by parceling audio into 100-ms frames and comparing, for each frame, human and LENA classifications. LENA correctly classified adult speech 67% of the time across families (average false negative rate: 33%). LENA's adult word count showed a mean +47% error relative to human counts. Classification and Adult Word Count error rates were significantly affected by talkers' gender and whether speech was addressed to a child or an adult. The largest systematic errors occurred when adult females addressed children. Results show LENA's classifications and Adult Word Count entailed random - and sometimes large - errors across recordings, as well as systematic errors as a function of talker gender and addressee. Due to systematic and sometimes high error in estimates of amount of adult language input, relying on this metric alone may lead to invalid clinical and/or research conclusions. Further validation studies and circumspect usage of LENA are warranted.

Toddlers' sensitivity to talker age in novel word learning: Children are better teachers

From early on, young children are sensitive to talker-specific attributes present in the speech signal. For example, infants attend selectively and learn better from their mother’s voice than another female voice. Since age influences vocal quality, we asked whether toddlers show similar selective attention and learning from talkers of specific ages. We recorded visual and auditory stimuli from 3 adult males and females and 3 boys and girls. In Experiment 1, 24 toddlers viewed two side-by-side video clips of two talkers reciting a nursery rhyme and heard a soundtrack that matched with either the age or gender of one of the two talkers. The results revealed that children were able to match both vocal age and gender attributes to visual attributes. In Experiment 2, 24 toddlers were tested in a novel word learning task with talkers of different ages and genders. The results revealed that toddlers learned novel words from child talkers but failed to learn from adult talkers. These results suggest that young learners are sensitive to talker age information in speech and are biased towards learning words from younger talkers. We discuss the origins of such a bias.From early on, young children are sensitive to talker-specific attributes present in the speech signal. For example, infants attend selectively and learn better from their mother’s voice than another female voice. Since age influences vocal quality, we asked whether toddlers show similar selective attention and learning from talkers of specific ages. We recorded visual and auditory stimuli from 3 adult males and females and 3 boys and girls. In Experiment 1, 24 toddlers viewed two side-by-side video clips of two talkers reciting a nursery rhyme and heard a soundtrack that matched with either the age or gender of one of the two talkers. The results revealed that children were able to match both vocal age and gender attributes to visual attributes. In Experiment 2, 24 toddlers were tested in a novel word learning task with talkers of different ages and genders. The results revealed that toddlers learned novel words from child talkers but failed to learn from adult talkers. These results suggest that young l...

The reliability and predictive validity of the Guidelines for Stalking Assessment and Management (SAM).

This study assessed the reliability and validity of the Guidelines for Stalking Assessment and Management (SAM), a structured professional judgment measure for assessing stalking risks. The SAM was completed retrospectively from file review for 146 adult stalkers (90.4% male) referred to a community-based forensic mental health service. Interrater reliability (IRR) was initially poor, but developing a strict definition of stalking currency and rescoring the SAM led to improvement. Based on the updated scoring, IRR was moderate for judgments about whether stalking was ongoing at the time of assessment, and fair to moderate for summary risk judgments. Both case prioritization (area under the curve [AUC] = .69) and risk for continued stalking (AUC = .76) ratings discriminated between groups, with high-risk stalkers 5-9 times as likely as low-risk stalkers to reoffend by stalking their original victims. Lifetime SAM total scores (AUC = .70) also featured moderate to good discrimination. Follow-up analyses suggested that this was driven mainly by the recent presence of risk markers and the nature of any ongoing stalking situation rather than historical or individual factors. Findings support the use of the SAM to structure risk judgments made by those with experience in assessing stalking. Current results also imply that IRR might be improved by introducing (a) a fixed definition of stalking currency and (b) usage guidelines for specific contexts. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Perception of talker height and sex from children’s voices

Several recent studies have investigated the ability of listeners to judge the height of adult talkers from their speech. Here, we examine the perception of talker height from a sample of /hVd/ syllables spoken by children ranging in age from 5 through 18 years, with 3 talkers of each sex at each age level. Twenty college students judged the height and sex of the talker for each trial. Perceptual estimates of height were moderately correlated with actual height (for males, r = 0.78; for females, r = 0.67). Consistent with our recent findings concerning the perception of talker age [Barreda & Assmann, JASA-EL 143(5), EL361, 2018], listeners' judgments of talker height appear to incorporate assumptions about talker sex and the relationships between speech acoustics and veridical height for male and female talkers of different heights. For example, when older girls were misidentified as boys, their height was likely to be underestimated. This behavior results in predictable error patterns in height judgments from speech: in situations where talker sex is misidentified, listeners apply the “wrong” acoustic model to estimate talker height, leading to correlated error patterns between apparent height and sex.

Effects of language experience and task demands on talker recognition by children and adults.

Talker recognition is a language-dependent process, with listeners recognizing talkers better when the talkers speak a familiar versus an unfamiliar language. This language familiarity effect (LFE) is firmly established in adults, but its developmental trajectory in children is not well understood. Some evidence suggests that the effect already exists in infancy, but little is known about how it unfolds in childhood. The present study explored whether the strength of the LFE increases in early childhood. Adults and children were tested in their native language and a foreign language using a "same-different" talker discrimination task and a "voice line-up" talker recognition task. Results showed that adults and 6-year-olds, but not 5-year-olds, exhibit a robust LFE, suggesting that the effect strengthens as children's language competence increases. For both adults and older children, the emergence of an LFE moreover appeared to be task-dependent. This study contributes to a better understanding of how children develop mature talker recognition abilities and when children's processing of indexical and linguistic information in speech approaches adult-like levels. Furthermore, the findings reported here contribute to the debates regarding the origins of the LFE-a hallmark of adult talker recognition.

Intelligibility of Noise-Adapted and Clear Speech in Child, Young Adult, and Older Adult Talkers.

This study examined intelligibility of conversational and clear speech sentences produced in quiet and in noise by children, young adults, and older adults. Relative talker intelligibility was assessed across speaking styles. Sixty-one young adult participants listened to sentences mixed with speech-shaped noise at -5 dB signal-to-noise ratio. The analyses examined percent correct scores across conversational, clear, and noise-adapted conditions and the three talker groups. Correlation analyses examined whether talker intelligibility is consistent across speaking style adaptations. Noise-adapted and clear speech significantly enhanced intelligibility for young adult listeners. The intelligibility improvement varied across the three talker groups. Notably, intelligibility benefit was smallest for children's speaking style modifications. Listeners also perceived speech produced in noise by older adults to be less intelligible compared to the younger talkers. Talker intelligibility was correlated strongly between conversational and clear speech in quiet, but not for conversational speech produced in quiet and in noise. Results provide evidence that intelligibility variation related to age and communicative barrier has the potential to aid clinical decision making for individuals with speech disorders, particularly dysarthria.

Do older and younger adult listeners show a “clear speech benefit” for speech produced by older adult talkers?

This study investigates whether a “clear speech benefit” is obtained for speech produced by older (OA) talkers and younger adult (YA) controls in a clear speaking style when heard in babble noise. The speech materials were recorded while OA and YA talkers read BKB sentences to a YA partner who repeated the sentence while hearing normally (NORM) or with a simulated hearing loss (HLS). The HLS condition naturally induced clear speech adaptations. 128 BKB sentences from 4 YA and 4 OA talkers (NORM, HLS) matched on a range of metrics were used in an adaptive listening test tracking the signal-to-noise ratio corresponding to 67% intelligibility. Listeners were 71 native British English listeners: 24 YA (M = 25.2 yrs), 27 OA-NH with normal hearing (M= 71.8), 20 OA-HL with presbyacusis (M= 73.7). Speech perception in noise was hardest for OA listeners, especially from OA-HL. SNR thresholds were significantly lower for YA than for OA voices. The clear speech benefit for HLS speech was only significant for YA voices for all listener groups. In summary, OA talkers were less intelligible than YA talkers regardless of listener age; clear speech adaptations by OA talkers did not result in enhanced intelligibility for OA or YA listeners.