Reduced Speech Rate Research Articles

Expansion in speech time can restore comprehension in a simultaneously speaking bilingual robot.

Introduction: In this study, the development of a social robot, capable of giving speech simultaneously in more than one language was in mind. However, the negative effect of background noise on speech comprehension is well-documented in previous works. This deteriorating effect is more highlighted when the background noise has speech-like properties. Hence, the presence of speech as the background noise in a simultaneously speaking bilingual robot can be fatal for the speech comprehension of each person listening to the robot. Methods: To improve speech comprehension and consequently, user experience in the intended bilingual robot, the effect of time expansion on speech comprehension in a multi-talker speech scenario was investigated. Sentence recognition, speech comprehension, and subjective evaluation tasks were implemented in the study. Results: The obtained results suggest that a reduced speech rate, leading to an expansion in the speech time, in addition to increased pause duration in both the target and background speeches can lead to statistically significant improvement in both sentence recognition, and speech comprehension of participants. More interestingly, participants got a higher score in the time-expanded multi-talker speech than in the standard-speed single-talker speech in the speech comprehension and, in the sentence recognition task. However, this positive effect could not be attributed merely to the time expansion, as we could not repeat the same positive effect in a time-expanded single-talker speech. Discussion: The results obtained in this study suggest a facilitating effect of the presence of the background speech in a simultaneously speaking bilingual robot provided that both languages are presented in a time-expanded manner. The implications of such a simultaneously speaking robot are discussed.

Non‐fluent/agrammatic variant of primary progressive aphasia with progressive supranuclear palsy

AbstractBackgroundNon‐fluent/agrammatic variante of primary progressive aphasia (nfvPPA) is a neurodegenerative disorder characterized by speech production impairment (1). The overlap of nfvPPA and progressive supranuclear palsy (PSP) and corticobasal syndrome cases have been reported (2). As nfvPPA progresses, a parkinsonian disorder often co‐occurs (3). There are different kinds of language impairment including articulatory deficits, agrammatism, reduced speech rate, and anomia (1). Here we present a Peruvian woman with nfvPPA with single‐photon emission computed tomography (SPECT) and parkinsonian syndrome.MethodWe describe a 73‐year‐old woman with progressive speech production impairment and parkinsonian syndrome. She completed standard neurological, neuropsychological, and speech‐language evaluations, as well as brain MRI and SPECT scan.ResultThe patient is a right‐handed woman with 16 years of education. No family history of dementia, parkinsonism or motor neuron disease was reported. At age 71, she presented progressive difficulty in speaking, anomia and verbal hesitancy; but she can understand conversations, send and read text messages. She also had depressive symptoms. MRI showed mild left frontal and perisylvian > right atrophy (fig 1).By age 73, she developed a prominent reduction in spontaneous speech, mild difficulties in reading and writing, occasional paraphasia, less empathy, dietary change, moria and, mild parkinsonism (she expresses less emotion, tremor, slowly walk and falls). Her episodic memory starts to decline thereafter.On examination, she had mild‐moderate telegraphic speech, imitation behavior, mild facial masking, bradykinesia and mild postural instability but no abnormal extraocular movement. Speech‐language assessment showed non‐fluent aphasia and apraxia of speech. Impaired comprehension of syntactically complex sentences. Naming was mildly impaired. Syntactic errors were present. Executive function was also impaired, but visuoperceptual skills were preserved.Serological analyses were unrevealing. Brain SPECT scan showed left frontal and perisylvian > right cortical hypoperfusion (fig 2).ConclusionWe report a Peruvian case of an elderly woman presenting with a 3‐year history of nfvPPA features and PSP. Her SPECT scan showed left frontal and perisylvian > right cortical hypoperfusion. Consider early evaluating motor function in nfvPPA patients in light of the possibility of CBS or PSP overlap.

Acoustic cues to non-native-directed speech

Facing linguistic barriers to communication, talkers spontaneously adjust their speech, facilitating perception by their listener. These adjustments characteristically involve hyperarticulation, such as reduced speech rate, increased vowel dispersion, and increased segmental duration. Listener-based hyperarticulation could result from listener modeling, in which the talker monitors their listener’s comprehension. Hyperarticulation could also result from rich phonological representations, in which listener-based variation is directly represented. This study examined predictions of monitoring and representational accounts of listener-based hyperarticulation using a perception task. Participants completed a forced-choice identification task which tasked them with identifying the background of an interlocutor from recorded speech. That speech was originally produced to imagined and real and to native and non-native interlocutors. If listener-based variation originates with listener modeling, accuracy should be high and similar for each listener background. If that variation originates from rich representations, accuracy should be low, variable, and different across listener backgrounds. The results revealed poor accuracy, even for speech directed toward imagined non-natives, the most hyperarticulate speech. Participants’ choices were influenced most by speech rate, second by vowel dispersion, but not by vowel duration. We discuss the implications of these results for cognitive models of listener-based phonetic variation.

Characteristics of Thai Agrammatic speech

ABSTRACT Background Agrammatic speech is characterized by reduced speech rate, reduced utterance length and lack of grammatical complexity, with grammatical morphemes often omitted or substituted. At the word level, verbs have been argued to be particularly vulnerable: agrammatic speakers produce fewer verbs or use a less diverse range of verbs than unimpaired speakers and the use of finite verbs is compromised. However, this description is based on agrammatic narrative speech from languages that express Tense, Aspect and Agreement through verb inflection. To date, a few studies have described narrative speech in a language without verb inflection (e.g., Standard Indonesian). Thai is another language that does not use verb inflection but uses constructions with serial verbs. Another typical feature of Thai, which has not been investigated in agrammatic speakers, is the use of particles to express politeness, although agrammatic speakers of Standard Indonesian have an impaired use of (different) particles but produce the passive construction (which is a way to express politeness) to a normal extent. Aim The current study aimed to characterize Thai agrammatic speech and to analyse the use of verbs and polite particles. Methods Nine Thai agrammatic and nine non-brain-damaged (NBD) speakers participated in the study. Narrative speech was elicited in a semi-standardized interview and by picture description. First, the presence of general features of agrammatic speech were investigated in Thai: reduced speech rate and utterance length, and lack of grammatical complexity. This was followed by an in-depth analysis of verb and particle production. Results As in other languages, Thai agrammatic speakers talked slowly and with short utterances. However, the use of embedded sentences was normal. They produced fewer verbs, more specifically, their production of the serial verb construction was seriously impaired. Remarkably, the use of polite particles was spared, in fact, the agrammatic speakers produced more of these particles than the NBD speakers, although this may have been influenced by the context. Conclusions Thai agrammatic speech resembles that of other languages in terms of speech rate and utterance length. Interestingly, the specific features of Thai that were investigated, serial verbs and polite particles, both showed different patterns to normal, and merit further investigation in the future.

Using Speech Data From Interactions With a Voice Assistant to Predict the Risk of Future Accidents for Older Drivers: Prospective Cohort Study.

BackgroundWith the rapid growth of the older adult population worldwide, car accidents involving this population group have become an increasingly serious problem. Cognitive impairment, which is assessed using neuropsychological tests, has been reported as a risk factor for being involved in car accidents; however, it remains unclear whether this risk can be predicted using daily behavior data.ObjectiveThe objective of this study was to investigate whether speech data that can be collected in everyday life can be used to predict the risk of an older driver being involved in a car accident.MethodsAt baseline, we collected (1) speech data during interactions with a voice assistant and (2) cognitive assessment data—neuropsychological tests (Mini-Mental State Examination, revised Wechsler immediate and delayed logical memory, Frontal Assessment Battery, trail making test-parts A and B, and Clock Drawing Test), Geriatric Depression Scale, magnetic resonance imaging, and demographics (age, sex, education)—from older adults. Approximately one-and-a-half years later, we followed up to collect information about their driving experiences (with respect to car accidents) using a questionnaire. We investigated the association between speech data and future accident risk using statistical analysis and machine learning models.ResultsWe found that older drivers (n=60) with accident or near-accident experiences had statistically discernible differences in speech features that suggest cognitive impairment such as reduced speech rate (P=.048) and increased response time (P=.040). Moreover, the model that used speech features could predict future accident or near-accident experiences with 81.7% accuracy, which was 6.7% higher than that using cognitive assessment data, and could achieve up to 88.3% accuracy when the model used both types of data.ConclusionsOur study provides the first empirical results that suggest analysis of speech data recorded during interactions with voice assistants could help predict future accident risk for older drivers by capturing subtle impairments in cognitive function.

Bilingualism in a Case of the Non-fluent/agrammatic Variant of Primary Progressive Aphasia

There is a growing body of research on language impairment in bilingual speakers with neurodegenerative diseases. Evidence as to which language is better preserved is rather inconclusive. Various factors seem to influence language performance, most notably age of acquisition, level of proficiency, immersion and degree of exposure to each language. The present study examined fluency, lexical, discourse and grammatical abilities of a Greek-French late bilingual man with the non-fluent/agrammatic variant of primary progressive aphasia (nfvPPA). Speech samples derived from three different narrative tasks in both languages were analyzed using quantitative production analysis (QPA) and fluency measures. The first aim of the study was to compare the participant’s connected speech production to that of Greek-speaking normal controls. The second aim was to determine whether Greek (L1) and French (L2) were differentially impaired. To our knowledge, this is the first report of connected speech deficits in a Greek-speaking patient with PPA and the first study which uses QPA to compare L1 and L2 narratives in a bilingual speaker with PPA. Compared to neurologically healthy controls, our participant was impaired in lexical, discourse and grammatical productivity measures, but did not differ in measures of grammatical accuracy. The presence of dysfluencies, reduced speech rate and simplified syntax is consistent with the pattern of impairment reported for the nfvPPA. Results showed that narrative production measures did not differ significantly between languages. However, they suggest a slightly worse performance in his second, non-dominant, language despite a similar pattern of impairment in both languages. Lengthy exposure to L2 and regular activation of L2 through daily use may explain the preservation of discourse abilities in his non-dominant language. This study calls attention to factors such as language dominance, proficiency, patterns of use and exposure to a language. These factors play a key role in assessing bilingual individuals with PPA and making clinical decisions.

Parálisis supranuclear progresiva: estudio longitudinal a partir del análisis acústico del habla

El objetivo de este estudio es medir de forma objetiva y cuantitativa los distintos parámetros del habla en un caso de Parálisis Supranuclear Progresiva durante un periodo de cuatro años. Se realizó un análisis acústico de la vocal sostenida /a/, del automatismo “1,2,3,4” y de la repetición rápida de las sílabas /pa/, /ta/, /ka/ y /pataka/. Se consideraron diversos parámetros: la frecuencia fundamental (F0), el tiempo máximo fonatorio (TMF), la intensidad, los formantes, el shimmer, el jitter, el ruido en relación con los armónicos (NHR), la duración y el número de sílabas, el “Voice Onset Time” (VOT), la tasa de habla, la tasa de silencios y los aspectos prosódicos del habla. Las alteraciones en la voz y en el habla evolucionan hacia la imprecisión articulatoria, una pobre calidad vocal, reducido TMF, reducida tasa del habla, disminución de la variabilidad de la entonación y pausas prolongadas en las diadococinesias. El análisis reveló la coincidencia en el tiempo entre el deterioro progresivo del habla en general y el elevado porcentaje de cierres incompletos en el VOT, con la disfagia

Motor speech signature of behavioral variant frontotemporal dementia: Refining the phenotype.

To provide a comprehensive description of motor speech function in behavioral variant frontotemporal dementia (bvFTD). Forty-eight individuals (24 bvFTD and 24 age- and sex-matched healthy controls) provided speech samples. These varied in complexity and thus cognitive demand. Their language was assessed using the Progressive Aphasia Language Scale and verbal fluency tasks. Speech was analyzed perceptually to describe the nature of deficits and acoustically to quantify differences between patients with bvFTD and healthy controls. Cortical thickness and subcortical volume derived from MRI scans were correlated with speech outcomes in patients with bvFTD. Speech of affected individuals was significantly different from that of healthy controls. The speech signature of patients with bvFTD is characterized by a reduced rate (75%) and accuracy (65%) on alternating syllable production tasks, and prosodic deficits including reduced speech rate (45%), prolonged intervals (54%), and use of short phrases (41%). Groups differed on acoustic measures derived from the reading, unprepared monologue, and diadochokinetic tasks but not the days of the week or sustained vowel tasks. Variability of silence length was associated with cortical thickness of the inferior frontal gyrus and insula and speech rate with the precentral gyrus. One in 8 patients presented with moderate speech timing deficits with a further two-thirds rated as mild or subclinical. Subtle but measurable deficits in prosody are common in bvFTD and should be considered during disease management. Language function correlated with speech timing measures derived from the unprepared monologue only.

Let silence speak about aphasia: possible associations between pause and language related cognitive processes

Let silence speak about aphasia: possible associations between pause and language related cognitive processes

Delayed auditory feedback simulates features of nonfluent primary progressive aphasia

The pathophysiology of nonfluent primary progressive aphasia (nfvPPA) remains poorly understood. Here, we compared quantitatively speech parameters in patients with nfvPPA versus healthy older individuals under altered auditory feedback, which has been shown to modulate normal speech output. Patients (n=15) and healthy volunteers (n=17) were recorded while reading aloud under delayed auditory feedback [DAF] with latency 0, 50 or 200ms and under DAF at 200ms plus 0.5 octave upward pitch shift. DAF in healthy older individuals was associated with reduced speech rate and emergence of speech sound errors, particularly at latency 200ms. Up to a third of the healthy older group under DAF showed speech slowing and frequency of speech sound errors within the range of the nfvPPA cohort. Our findings suggest that (in addition to any anterior, primary language output disorder) these key features of nfvPPA may reflect distorted speech input signal processing, as simulated by DAF. DAF may constitute a novel candidate pathophysiological model of posterior dorsal cortical language pathway dysfunction in nfvPPA.

I01 Impaired Motor Speech Performance in Premotor Stages of Huntington's Disease (HD) over time - A Longitudinal Investigation

<h3>Background</h3> Pace and rhythm of speech and non-speech vocal utterances have recently been shown to be abnormal in speakers with manifest HD and are characterised by a reduced speech rate and irregularities of syllable repetition. On the other hand, speakers with premanifest HD already feature abnormalities of syllable repetition, however, speech rate has been found to be higher than in healthy controls. Therefore, longitudinal studies in premanifest HD subjects should be helpful to illustrate the evolution of the abnormal patterns over time. <h3>Aim</h3> The aim of the study was to survey the development of distinctive parameters of speech and non-speech vocal performance in the time course of premanifest Huntington9s disease (HD). <h3>Methods</h3> We examined 13 speakers with premanifest HD which were tested and re-tested after 22 months using a speech task consisting of a) reading a German text (for the calculation of net speech rate/NSR and pause ratio/PR%) and b) several subtests for the monitoring of non-speech vocal performance to calculate the maximum syllable repetition capacity/maxSylRep and the precision of syllable in a self-chosen steady pace (the coefficient of variance/COV displayed the steadiness of repetition). <h3>Results</h3> Disease specific variables as overall motor impairment and the cognitive score became worse over time. Furthermore, in the speech tasks, there was a tendency to a reduction of NSR and maxSylRep and further decline of the steadiness of syllable repetition. The self-chosen pace of syllable repetition was significantly slower at follow-up (p &lt; 0.0001). Moreover, there was a correlation between the reduction of the MRI based volume of the caudate nucleus and a worsening of syllable repetition over time. <h3>Conclusions</h3> Abnormalities of speech rate and rhythm are detectable even in the premanifest stages of HD and show a tendency to further deteriorate in the time course of disease progression. Further long-term follow-up studies are warranted to survey the evolution of these distinctive patterns with time which might be helpful for the monitoring of disease progression and could provide some further insight into the underlying pathophysiology of HD.

Cognitive–Perceptual Examination of Remediation Approaches to Hypokinetic Dysarthria

To determine how increased vocal loudness and reduced speech rate affect listeners' cognitive-perceptual processing of hypokinetic dysarthric speech associated with Parkinson's disease. Fifty-one healthy listener participants completed a speech perception experiment. Listeners repeated phrases produced by 5 individuals with dysarthria across habitual, loud, and slow speaking modes. Listeners were allocated to habitual ( n = 17), loud ( n = 17), or slow ( n = 17) experimental conditions. Transcripts derived from the phrase repetition task were coded for overall accuracy (i.e., intelligibility), and perceptual error analyses examined how these conditions affected listeners' phonemic mapping (i.e., syllable resemblance) and lexical segmentation (i.e., lexical boundary error analysis). Both speech conditions provided obvious perceptual benefits to listeners. Overall, transcript accuracy was highest in the slow condition. In the loud condition, however, improvement was evidenced across the experiment. An error analysis suggested that listeners in the loud condition prioritized acoustic-phonetic cues in their attempts to resolve the degraded signal, whereas those in the slow condition appeared to preferentially weight lexical stress cues. Increased loudness and reduced rate exhibited differential effects on listeners' perceptual processing of dysarthric speech. The current study highlights the insights that may be gained from a cognitive-perceptual approach.

The confidence of speech-language pathology students regarding communicating with people with aphasia.

BackgroundAphasia is an acquired language disorder that can present a significant barrier to patient involvement in healthcare decisions. Speech-language pathologists (SLPs) are viewed as experts in the field of communication. However, many SLP students do not receive practical training in techniques to communicate with people with aphasia (PWA) until they encounter PWA during clinical education placements.MethodsThis study investigated the confidence and knowledge of SLP students in communicating with PWA prior to clinical placements using a customised questionnaire. Confidence in communicating with people with aphasia was assessed using a 100-point visual analogue scale. Linear, and logistic, regressions were used to examine the association between confidence and age, as well as confidence and course type (graduate-entry masters or undergraduate), respectively. Knowledge of strategies to assist communication with PWA was examined by asking respondents to list specific strategies that could assist communication with PWA.ResultsSLP students were not confident with the prospect of communicating with PWA; reporting a median 29-points (inter-quartile range 17–47) on the visual analogue confidence scale. Only, four (8.2%) of respondents rated their confidence greater than 55 (out of 100). Regression analyses indicated no relationship existed between confidence and students‘ age (p = 0.31, r-squared = 0.02), or confidence and course type (p = 0.22, pseudo r-squared = 0.03). Students displayed limited knowledge about communication strategies. Thematic analysis of strategies revealed four overarching themes; Physical, Verbal Communication, Visual Information and Environmental Changes. While most students identified potential use of resources (such as images and written information), fewer students identified strategies to alter their verbal communication (such as reduced speech rate).ConclusionsSLP students who had received aphasia related theoretical coursework, but not commenced clinical placements with PWA, were not confident in their ability to communicate with PWA. Students may benefit from an educational intervention or curriculum modification to incorporate practical training in effective strategies to communicate with PWA, before they encounter PWA in clinical settings. Ensuring students have confidence and knowledge of potential communication strategies to assist communication with PWA may allow them to focus their learning experiences in more specific clinical domains, such as clinical reasoning, rather than building foundation interpersonal communication skills.

Speech and pause characteristics associated with voluntary rate reduction in Parkinson's disease and Multiple Sclerosis

The primary purpose of this study was to investigate how speakers with Parkinson's disease (PD) and Multiple Sclerosis (MS) accomplish voluntary reductions in speech rate. A group of talkers with no history of neurological disease was included for comparison. This study was motivated by the idea that knowledge of how speakers with dysarthria voluntarily accomplish a reduced speech rate would contribute toward a descriptive model of speaking rate change in dysarthria. Such a model has the potential to assist in identifying rate control strategies to receive focus in clinical treatment programs and also would advance understanding of global speech timing in dysarthria. All speakers read a passage in Habitual and Slow conditions. Speech rate, articulation rate, pause duration, and pause frequency were measured. All speaker groups adjusted articulation time as well as pause time to reduce overall speech rate. Group differences in how voluntary rate reduction was accomplished were primarily one of quantity or degree. Overall, a slower-than-normal rate was associated with a reduced articulation rate, shorter speech runs that included fewer syllables, and longer more frequent pauses. Taken together, these results suggest that existing skills or strategies used by patients should be emphasized in dysarthria training programs focusing on rate reduction. Results further suggest that a model of voluntary speech rate reduction based on neurologically normal speech shows promise as being applicable for mild to moderate dysarthria. Learning outcomes: The reader will be able to: (1) describe the importance of studying voluntary adjustments in speech rate in dysarthria, (2) discuss how speakers with Parkinson's disease and Multiple Sclerosis adjust articulation time and pause time to slow speech rate.

Conceptual proposition selection and the LIFG: Neuropsychological evidence from a focal frontal group

Much debate surrounds the role of the left inferior frontal gyrus (LIFG). Evidence from lesion and neuroimaging studies suggests the LIFG supports a selection mechanism used in single word generation. Single case studies of dynamic aphasic patients with LIFG damage concur with this and extend the finding to selection of sentences at the conceptual preparation stage of language generation. A neuropsychological group with unselected focal frontal and non-frontal lesions is assessed on a sentence generation task that varied the number of possible conceptual propositions available for selection. Frontal patients with LIFG damage when compared to Frontal patients without LIFG damage and Posterior patients were selectively impaired on sentence generation tests only when stimuli activated multiple conceptual propositions that compete with each other for selection. We found that this selective impairment is critical for reduced speech rate, the core deficit of dynamic aphasia, and we would argue it is causative for one form of dynamic aphasia associated with LIFG lesions. These results provide evidence that the LIFG is crucial for selecting among multiple competing conceptual propositions for language generation.

Influences of Infant-Directed Speech on Early Word Recognition.

When addressing infants, many adults adopt a particular type of speech, known as infant-directed speech (IDS). IDS is characterized by exaggerated intonation, as well as reduced speech rate, shorter utterance duration, and grammatical simplification. It is commonly asserted that IDS serves in part to facilitate language learning. Although intuitively appealing, direct empirical tests of this claim are surprisingly scarce. Additionally, studies that have examined associations between IDS and language learning have measured learning within a single laboratory session rather than the type of long-term storage of information necessary for word learning. In this study, 7- and 8-month-old infants' long-term memory for words was assessed when words were spoken in IDS and adult-directed speech (ADS). Word recognition over the long term was successful for words introduced in IDS, but not for those introduced in ADS, regardless of the register in which recognition stimuli were produced. Findings are discussed in the context of the influence of particular input styles on emergent word knowledge in prelexical infants.

Living with Dysarthria: Evaluation of a Self-Report Questionnaire

The study describes an effort to evaluate the speech difficulties as perceived by individuals with dysarthria. A self-report questionnaire, Living with Neurologically Based Speech Difficulties (Living with Dysarthria), was answered by 55 individuals with varying types and degrees of dysarthria. Results show that both type and degree of subjectively perceived communicative difficulties varied. Degree of communicative difficulties was not related to age, gender, diagnosis, disease duration or employment status in this group. Generally, the overriding problems were related to restrictions in communicative participation, possibilities to actively take part in work and studies and to express one’s personality were particularly affected. Communication was also affected by emotions and by the number and familiarity of people present in communicative encounters. The dominating speech difficulties were related to reduced speech rate and a need for repetition as a consequence of misunderstandings. A statistically nonsignificant difference was found between the higher mean of the group with moderate dysarthria compared to the groups with severe and mild dysarthria, indicating that severity of dysarthria does not necessarily predict extent of perceived communicative difficulties. It is concluded that systematic subjective reports should always be included in the assessment of individuals with acquired dysarthria.

Perceptual and acoustic analysis of speech in individuals with spinocerebellar ataxia (SCA)

With current progress in genetic research, autosomal, dominant, hereditary, neurodegenerative diseases, affecting the cerebellum and cerebellar connections, are increasingly diagnosed as spinocerebellar ataxias (SCA). In the present study speech samples from 21 subjects with spinocerebellar ataxia (SCA), and 21 matched control subjects were analyzed using perceptual and acoustic methodology. Dysarthria assessment showed that subjects had mild or mild-moderate dysarthria. Perceptual analysis indicated that equalized stress, imprecise consonants, vocal instability, monotony and reduced speech rate were the speech parameters that yielded the highest mean perceptual ratings. A factor analysis of perceptual speech parameters revealed two main factors: Factor 1 was associated with articulatory timing and Factor 2 with vocal quality. Acoustic analysis revealed significantly reduced speech rate during text reading, reduced alternating and sequential motion rates (AMR/SMR), significantly longer and more variable syllable and pause durations, and significantly higher vocal instability for subjects with SCA compared to control subjects.

Aided and Unaided Speech Supplementation Strategies

This study compared the influence of speaker-implemented iconic hand gestures and alphabet cues on speech intelligibility scores and strategy helpfulness ratings for 3 adults with cerebral palsy and dysarthria who differed from one another in their overall motor abilities. A total of 144 listeners (48 per speaker) orthographically transcribed sentences spoken with alphabet cues (aided), iconic hand gestures (unaided), and a habitual speech control condition; scores were compared within audio-visual and audio-only listening formats. When listeners were presented with simultaneous audio and visual information, both alphabet cues and hand gestures resulted in higher intelligibility scores and higher helpfulness ratings than the no-cues control condition for each of the 3 speakers. When listeners were presented with only the audio signal, alphabet cues and gestures again resulted in higher intelligibility scores than no cues for 2 of the 3 speakers. Temporal acoustic analyses showed that alphabet cues had consistent effects on speech production, including reduced speech rate, reduced articulation rate, and increased frequency and duration of pauses. Findings for gestures were less consistent, with marked differences noted among speakers. Results illustrate that individual differences play an important role in the value of supplemental augmentative and alternative communication strategies and that aided and unaided strategies can have similar positive effects on the communication of speakers with global motor impairment.

The costs of doing two things at once for young and older adults: talking while walking, finger tapping, and ignoring speech or noise.

Young and older adults provided language samples in response to questions while walking, finger tapping, and ignoring speech or noise. The language samples were scored on 3 dimensions: fluency, complexity, and content. The hypothesis that working memory limitations affect speech production by older adults was tested by comparing baseline samples with those produced while the participants were performing the concurrent tasks. There were baseline differences: Older adults' speech was less fluent and less complex than young adults' speech. Young adults adopted a different strategy in response to the dual-task demands than older adults: They reduced sentence length and grammatical complexity. In contrast, older adults shifted to a reduced speech rate in the dual-task conditions.