Explore the vast range of titles available.

Purpose: The impact of clear speech, increased vocal intensity, and rate reduction on acoustic characteristics of vowels was compared in speakers with Parkinson's disease (PD), speakers with multiple sclerosis (MS), and healthy controls. Method: Speakers read sentences in habitual, clear, loud, and slow conditions. Variations in clarity, intensity, and rate were stimulated using magnitude production. Formant frequency values for peripheral and nonperipheral vowels were obtained at 20%, 50%, and 80% of vowel duration to derive static and dynamic acoustic measures. Intensity and duration measures were obtained. Results: Rate was maximally reduced in the slow condition, and vocal intensity was maximized in the loud condition. The clear condition also yielded a reduced articulatory rate and increased intensity, although less than for the slow or loud conditions. Overall, the clear condition had the most consistent impact on vowel spectral characteristics. Spectral and temporal distinctiveness for peripheral-nonperipheral vowel pairs was largely similar across conditions. Conclusions: Clear speech maximized peripheral and nonperipheral vowel space areas for speakers with PD and MS while also reducing rate and increasing vocal intensity. These results suggest that a speech style focused on increasing articulatory amplitude yields the most robust changes in vowel segmental articulation.

Purpose: Age-related sensorineural hearing loss can dramatically affect speech recognition performance due to reduced audibility and suprathreshold distortion of spectrotemporal information. Normal aging produces changes within the central auditory system that impose further distortions. The goal of this study was to characterize the effects of aging and hearing loss on perceptual representations of speech. Method: We asked whether speech intelligibility is supported by different patterns of spectrotemporal modulations (STMs) in older listeners compared to young normal-hearing listeners. We recruited 3 groups of participants: 20 older hearing-impaired (OHI) listeners, 19 age-matched normal-hearing listeners, and 10 young normal-hearing (YNH) listeners. Listeners performed a speech recognition task in which randomly selected regions of the speech STM spectrum were revealed from trial to trial. The overall amount of STM information was varied using an up-down staircase to hold performance at 50% correct. Ordinal regression was used to estimate weights showing which regions of the STM spectrum were associated with good performance (a \"classification image\" or CImg). Results: The results indicated that (a) large-scale CImg patterns did not differ between the 3 groups; (b) weights in a small region of the CImg decreased systematically as hearing loss increased; (c) CImgs were also nonsystematically distorted in OHI listeners, and the magnitude of this distortion predicted speech recognition performance even after accounting for audibility; and (d) YNH listeners performed better overall than the older groups. Conclusion: We conclude that OHI/older normal-hearing listeners rely on the same speech STMs as YNH listeners but encode this information less efficiently.

Purpose: Supportive semantic and syntactic information can increase children's and adults' word recognition accuracy in adverse listening conditions. However, there are inconsistent findings regarding how a talker's accent or dialect modulates these context effects. Here, we compare children's and adults' abilities to capitalize on sentence context to overcome misleading acoustic-phonetic cues in nonnative-accented speech. Method: Monolingual American English-speaking 5- to 7-year-old children ( n = 90) and 18- to 35-year-old adults ( n = 30) were presented with full sentences or the excised final word from each of the sentences and repeated what they heard. Participants were randomly assigned to 1 of 2 conditions: native-accented (Midland American English) or nonnative-accented (Spanish- and Japanese-accented English) speech. Participants also completed the NIH Toolbox Picture Vocabulary Test. Results: Children and adults benefited from sentence context for both native- and nonnative-accent talkers, but the benefit was greater for nonnative than native talkers. Furthermore, adults showed a greater context benefit than children for nonnative talkers, but the 2 age groups showed a similar benefit for native talkers. Children's age and vocabulary scores both correlated with context benefit. Conclusions: The cognitive-linguistic development that occurs between the early school-age years and adulthood may increase listeners' abilities to capitalize on top-down cues for lexical identification with nonnative-accented speech. These results have implications for the perception of speech with source degradation, including speech sound disorders, hearing loss, or signal processing that does not faithfully represent the original signal.

Memory consolidation resulting from sleep has been seen broadly: in verbal list learning 1 , spatial learning 2 , 3 , and skill acquisition in visual 4 , 5 , 6 , 7 , 8 and motor 9 , 10 , 11 tasks. These tasks do not generalize across spatial locations or motor sequences, or to different stimuli in the same location 5 , 11 , 12 . Although episodic rote learning constitutes a large part of any organism's learning, generalization is a hallmark of adaptive behaviour 13 . In speech, the same phoneme often has different acoustic patterns depending on context. Training on a small set of words improves performance on novel words using the same phonemes but with different acoustic patterns, demonstrating perceptual generalization 14 . Here we show a role of sleep in the consolidation of a naturalistic spoken-language learning task that produces generalization of phonological categories across different acoustic patterns. Recognition performance immediately after training showed a significant improvement that subsequently degraded over the span of a day's retention interval, but completely recovered following sleep. Thus, sleep facilitates the recovery and subsequent retention of material learned opportunistically at any time throughout the day. Performance recovery indicates that representations and mappings associated with generalization are refined and stabilized during sleep.

Purpose: The aim of this study was to investigate how deep brain stimulation (DBS) of the caudal zona incerta (cZi) affects speech intelligibility in persons with essential tremor. Method: Thirty-five participants were evaluated: off stimulation, on chronic stimulation optimized to alleviate tremor, and during unilateral stimulation at increasing amplitude levels. At each stimulation condition, the participants read 10 unique nonsense sentences from the Swedish Test of Intelligibility. Two listeners, blinded to stimulation condition, transcribed all recorded sentences orthographically in a randomized procedure. A mean speech intelligibility score for each patient and stimulation condition was computed, and comparisons were made between scores off and on stimulation. Results: Chronic cZi-DBS had no significant effect on speech intelligibility, and there was no difference in outcome between bilateral and unilateral treatments. During unilateral stimulation at increasing amplitudes, nine participants demonstrated deteriorating speech intelligibility. These nine participants were on average older and had more superior contacts activated during the evaluation compared with the participants without deterioration. Conclusions: Chronic cZi-DBS, optimized for tremor suppression, does not generally affect speech intelligibility in persons with essential tremor. Furthermore, speech intelligibility may be preserved in many individuals, even when stimulated at high amplitudes. Adverse effects of high-amplitude unilateral stimulation observed in this study were associated with stimulation originating from a more superior location, as well as with the participants' age. These results, highlighting age and stimulation location as contributing to speech intelligibility outcomes, were, however, based on a limited number of individuals experiencing adverse effects with high-amplitude stimulation and should, therefore, be interpreted with caution.

Purpose: Improving the ability to listen efficiently in noisy environments is a critical goal for hearing rehabilitation. However, understanding of the impact of difficult listening conditions on language processing is limited. The current study evaluated the neural processes underlying semantics in challenging listening conditions. Method: Thirty adults with normal hearing completed an auditory sentence processing task in 4-talker babble. Event-related brain potentials were elicited by the final word in high- or low-context sentences, where the final word was either highly expected or not expected, followed by a 4-alternative forced-choice response with either longer (1,000 ms), middle (700 ms), or shorter (400 ms) response time deadlines (RTDs). Results: Behavioral accuracy was reduced, and reactions times were faster for shorter RTDs. N400 amplitudes, reflecting ease of lexical access, were larger when elicited by target words in low-context sentences followed by shorter compared with longer RTDs. Conclusions These results reveal that more neural resources are allocated for semantic processing/lexical access when listening difficulty increases. Differences between RTDs may reflect increased attentional allocation for shorter RTDs. These findings suggest that situational listening demands can impact the demands for cognitive resources engaged in language processing, which could significantly impact listener experiences across environments.

Objective To investigate the influence of timing of hard palate closure on early speech development from 18 months to 3 years of age. Design A prospective, randomized clinical trial. Participants Thirty-four children with unilateral cleft lip and palate (UCLP) with velum closure at 4 months of age, and hard palate closure at 12 months (early hard palate repair, EarlyHPR) or 36 months (late hard palate unrepaired, LateHPU) by random assignment. Thirty-five control children were matched for gender and age. Methods All children were video recorded during a play interaction with a parent at 18 months of age. These recordings were transcribed according to the International Phonetic Alphabet. At 36 months a single word naming test was administered. Results At 18 months the LateHPU group produced fewer labial stops and more velar stops than the EarlyHPR group. Unlike the EarlyHPR group, the LateHPU group produced fewer vocalizations, consonants, and consonants permissible in word-initial position than the control group. Additionally, both cleft palate groups had a smaller productive vocabulary than the control group, but unlike the EarlyHPR group, the LateHPU group produced a smaller number of word tokens in social interaction than the control group. By 3 years of age, the LateHPU group had a (severely) restricted phonological system and produced more cleft speech characteristics than the EarlyHPR group. Conclusions Surgical timing of hard palate repair in a two-stage procedure appears to have an influence on early speech development in children with cleft palate.

Objectives To investigate the effects of l‐dopa (Levodopa) and cZi‐DBS (deep brain stimulation in caudal zona incerta) on spontaneous speech intelligibility in patients with PD (Parkinson's disease). Materials and Methods Spontaneous utterances were extracted from anechoic recordings from 11 patients with PD preoperatively (off and on l‐dopa medication) and 6 and 12 months post bilateral cZi‐DBS operation (off and on stimulation, with simultaneous l‐dopa medication). Background noise with an amplitude corresponding to a clinical setting was added to the recordings. Intelligibility was assessed through a transcription task performed by 41 listeners in a randomized and blinded procedure. Results A group‐level worsening in spontaneous speech intelligibility was observed on cZi stimulation compared to off 6 months postoperatively (8 adverse, 1 positive, 2 no change). Twelve months postoperatively, adverse effects of cZi‐DBS were not frequently observed (2 positive, 3 adverse, 6 no change). l‐dopa administered preoperatively as part of the evaluation for DBS operation provided the overall best treatment outcome (1 adverse, 4 positive, 6 no change). Conclusions cZi‐DBS was shown to have smaller negative effects when evaluated from spontaneous speech compared to speech effects reported previously. The previously reported reduction in word‐level intelligibility 12 months postoperatively was not transferred to spontaneous speech for most patients. Reduced intelligibility due to cZi stimulation was much more prominent 6 months postoperatively than at 12 months. Treatment effects on spontaneous speech intelligibility was assessed for patients with Parkinson's disease preoperatively (Levodopa treatment) and 6 and 12 months post deep brain stimulation operation targeting the caudal zona incerta (cZi‐DBS). The results showed negative/positive preoperative effects of Levodopa treatment, adverse effects of cZi‐DBS 6 months postoperatively, and no effect of cZi‐DBS 12 months postoperatively.

Objective The aim of this trial was to compare the relative effectiveness (efficacy and morbidity) of two surgical procedures for correcting velopharyngeal insufficiency (VPI). Design This was an international multicenter randomized trial to study the outcome of two surgical procedures (flap and sphincter pharyngoplasty) for speech, incidence of sleep apnea, and surgical complications. Method Ninety-seven patients 3 to 25 years old with repaired cleft palate and previously identified VPI were enrolled from five centers in the United States, Norway, and the U.K. Data were collected at presurgery, 3 months postsurgery, and 12 months postsurgery for subsequent analysis blind to the procedure. Main outcome measures included perceptual speech parameters, sleep apnea, nasalance measures, endoscopic features, and surgical complications. Results Groups for both surgical procedures achieved a high level of clinical improvement. At 3 months postsurgery, elimination of hypernasal resonance was achieved in twice as many patients after the flap procedure. This reached significance. However, at 12 months postsurgery, no statistically significant difference in outcomes remained between the two procedures for resonance, nasalance, endoscopic outcomes, or surgical complications. Flap and sphincter pharyngoplasty rarely resulted in clinically significant sleep apnea, and no difference was detected between the two procedures in the long-term incidence of sleep apnea. Conclusions Despite strongly held views in the literature concerning the relative effectiveness and safety of flap and sphincter pharyngoplasty, no significant differences were detected 1 year postoperatively.

This study assessed the ability of three acoustic measures of vowel space, two token-based and one trajectory-based, to quantify speech differences in people with Parkinson’s disease compared to controls and correlations with speech intelligibility. Fifty-six speakers (28 people with Parkinson’s and 28 controls) read a custom reading passage containing corner vowels. For token-based measures, the triangular vowel space area (tVSA) in kHz 2 and the unitless ratio of vowel articulation index (VAI) were calculated. For the trajectory-based measure, the articulatory-acoustic vowel space (AAVS) in kHz 2 was calculated. Speakers also read five unique sentences varying in word length, which were used to collect speech intelligibility ratings. Analyses of Variance revealed that all vowel space measures yielded group differences. Binary logistic regression revealed that only the token-based measures were able to statistically discriminate PwPD from controls, however all models performed poorly (R 2 < 0.113). Linear regressions showed that token-based metrics were statistically related to intelligibility and that the VAI yielded the best model for the current sample. The results support that token-based measures are well-suited for quantifying changes in acoustic vowel space and perceived speech intelligibility in people with Parkinson’s. Future work should examine the generalizability of these findings to other motor speech disorders as well as across different speech stimuli.