Types Of Speech Stimuli Research Articles

Perceptual Pattern of Cleft-Related Speech: A Task-fMRI Study on Typical Mandarin-Speaking Adults.

Congenital cleft lip and palate is one of the common deformities in the craniomaxillofacial region. The current study aimed to explore the perceptual pattern of cleft-related speech produced by Mandarin-speaking patients with repaired cleft palate using the task-based functional magnetic resonance imaging (task-fMRI) technique. Three blocks of speech stimuli, including hypernasal speech, the glottal stop, and typical speech, were played to 30 typical adult listeners with no history of cleft palate speech exploration. Using a randomized block design paradigm, the participants were instructed to assess the intelligibility of the stimuli. Simultaneously, fMRI data were collected. Brain activation was compared among the three types of speech stimuli. Results revealed that greater blood-oxygen-level-dependent (BOLD) responses to the cleft-related glottal stop than to typical speech were localized in the right fusiform gyrus and the left inferior occipital gyrus. The regions responding to the contrast between the glottal stop and cleft-related hypernasal speech were located in the right fusiform gyrus. More significant BOLD responses to hypernasal speech than to the glottal stop were localized in the left orbital part of the inferior frontal gyrus and middle temporal gyrus. More significant BOLD responses to typical speech than to the glottal stop were localized in the left inferior temporal gyrus, left superior temporal gyrus, left medial superior frontal gyrus, and right angular gyrus. Furthermore, there was no significant difference between hypernasal speech and typical speech. In conclusion, the typical listener would initiate different neural processes to perceive cleft-related speech. Our findings lay a foundation for exploring the perceptual pattern of patients with repaired cleft palate.

Использование приема «заинтересованных лиц» как основа методики обучения студентов направления «Туризм» устной иноязычной речи с опорой на текстовой материал

The aim of the study is to develop a methodology for teaching a foreign language utterance by using the “interested parties” technique based on textual material of different genres, taking into account the training of students in the “Tourism” direction. The article presents three stages of work according to the developed methodology, taking into account the categorization of interested parties’ names that are thematically relevant for the sphere of leisure and tourism; a set of speech exercises is proposed depending on different types of speech stimuli. The scientific novelty is determined by the introduction into scientific use of a new definition of the notion of “interested parties” from the point of view of the methodology for teaching students of non-linguistic areas, as well as the development and description of a three-stage methodology for teaching oral foreign speech, based on the presented categories of interested parties. As a result, a methodology was created for teaching oral foreign language based on textual material to students of the direction “Tourism”, consisting of a system of exercises in accordance with the stages of students’ speech skills formation, improved through the use of “interested parties” technique.

The perception of synthetic speech versus natural speech stimuli in adult listeners

The majority of speech perception research investigates interpersonal perception through presentation of two types of stimuli: synthetic speech and/or natural speech. Synthetically created speech stimuli allows for precisely controlled manipulation of individual acoustic variables, but can sound unnatural calling into questions its ecological validity. Alternatively, natural speech preserves the full complement of redundant acoustic cues yet limits control of specific acoustic parameters. In this study, we investigate speech discrimination comparing perception of specified acoustic parameters (formant transition duration, F3 onset frequency, F3-F2 distance) across three types of speech stimuli: synthetic speech stimuli, natural speech of a standard adult speaker, and each participant’s own voice. We use the Wide Range Acoustic Accuracy Scale (WRAAS), a computer-based perceptual assessment that uses a parameter estimation by sequential testing (PEST) adaptive-tracking algorithm to rapidly identify a listener’s ability to discriminate sounds. Most trials are presented near the Just-Noticeable-Difference (JND) of a stimulus continuum; thus, few trials are “wasted” with obviously same or different sounds. This study of typical adult listeners (n = 20, enrollment is ongoing) will provide baseline data for future work investigating perception of these same stimuli in children.

Situational Awareness: The Effect of Stimulus Type and Hearing Protection on Sound Localization.

The purpose of the current study was to test sound localization of a spoken word, rarely studied in the context of localization, compared to pink noise and a gunshot, while taking into account the source position and the effect of different hearing protection devices (HPDs) used by the listener. Ninety participants were divided into three groups using different HPDs. Participants were tested twice, under with- and no-HPD conditions, and were requested to localize the different stimuli that were delivered from one of eight speakers evenly distributed around them (starting from 22.5°). Localization of the word stimulus was more difficult than that of the other stimuli. HPD usage resulted in a larger mean root-mean-square error (RMSE) and increased mirror image reversal errors for all stimuli. In addition, HPD usage increased the mean RMSE and mirror image reversal errors for stimuli delivered from the front and back, more than for stimuli delivered from the left and right. HPDs affect localization, both due to attenuation and to limitation of pinnae cues when using earmuffs. Difficulty localizing the spoken word should be considered when assessing auditory functionality and should be further investigated to include HPDs with different attenuation spectra and levels, and to further types of speech stimuli.

Evaluation of Diadochokinesis in Greek Preschoolers With Speech Sound Disorders Using a Diadochokinetic Rates Protocol

The study aimed at evaluating the diadochokinetic (DDK) skills of Greek-speaking preschool children with phonological disorder (PD) by means of a structured evaluation protocol and at proposing cut-off points for children at risk of speech impairment. The participants were 36 children with PD and 60 typically developing (TD) peers. The groups were matched on age and gender. The PD group performed significantly slower than the TD group in all speech DDK tasks but not in the oral-motor tasks. The ROC analysis showed a statistically significant positive discrimination for all speech tasks. The internal consistency of the protocol was excellent (Cronbach’s α = .844), while complex stimuli showed a better discriminatory ability. The obtained results agree with Dodd’s classification for speech sound disorders (SSDs). Different types of speech stimuli must be included in the evaluation of DDK performance as a clinical predictor for preschoolers with SSDs who face difficulties in speech maturation.

Development of Minimal Pair Test in Tamil (MPT-T)

Introduction: Speech perception testing provides an accurate measurement of the child’s ability to perceive and distinguish the various phonetic segments and patterns of the sounds. From among the many types of speech stimuli used, minimal pairs can also be used to assess the phoneme recognition skills. Thus, the study focused on developing Minimal Pair Test in Tamil (MPT-T). Aim: The aim of the present study was to develop and validate the MPT in Tamil on Normal Hearing (NH) children and paediatric cochlear implantees (CI). Materials and Methods: It was an experimental study which included school going children in the age range of six to eight years and the duration of the study was 12 months. The test was developed in two phases. The first phase focussed on the construction of the word list, recording of the word pairs and the preparation of the test. The second phase was administration of the test on NH children and paediatric cochlear implantees. The test scores were analysed using Mann Whitney U test, Kruskal Wallis and Wilcoxon signed-rank test. The results showed a statistical significance between the NH group and the paediatric cochlear implantees. Results: The present study included 40 NH children and 15 paediatric cochlear implantees through purposive sampling method. The specific speech feature analysis of the paediatric cochlear implantees revealed that there was difficulty identifying the word pairs differing in Vowel Length (VL) and the best performed feature was Place of Articulation (POA). The results showed statistical significance between the NH group and the paediatric cochlear implantees. Conclusion: The developed test can be effectively used in clinic for assessing speech perception abilities of pediatric Cochlear Implantees and also in planning the rehabilitative goals.

The Effect of Signal to Noise Ratio on Cortical Auditory-Evoked Potentials Elicited to Speech Stimuli in Infants and Adults With Normal Hearing.

Identification and discrimination of speech sounds in noisy environments is challenging for adults and even more so for infants and children. Behavioral studies consistently report maturational differences in the influence that signal to noise ratio (SNR) and masker type have on speech processing; however, few studies have investigated the neural mechanisms underlying these differences at the level of the auditory cortex. In the present study, we investigated the effect of different SNRs on speech-evoked cortical auditory-evoked potentials (CAEPs) in infants and adults with normal hearing. A total of 10 adults (mean age 24.1 years) and 15 infants (mean age 30.7 weeks), all with normal hearing, were included in the data analyses. CAEPs were evoked to /m/ and /t/ speech stimuli (duration: 79 ms) presented at 75 dB SPL in the sound field with a jittered interstimulus interval of 1000-1200 ms. Each of the stimuli were presented in quiet and in the presence of white noise (SNRs of 10, 15, and 20 dB). Amplitude and latency measures were compared for P1, N1, and P2 for adults and for the large positivity (P) and following negativity (N: N250 and/or N450) for infants elicited in quiet and across SNR conditions. Infant P-N responses to /t/ showed no statistically significant amplitude and latency effects across SNR conditions; in contrast, infant CAEPs to /m/ were greatly reduced in amplitude and delayed in latency. Responses were more frequently absent for SNRs of 20 dB or less. Adult P1-N1-P2 responses were present for all SNRs for /t/ and most SNRs for /m/ (two adults had no responses to /m/ for SNR 10); significant effects of SNR were found for P1, N1, and P2 amplitude and latencies. The findings of the present study support that SNR effects on CAEP amplitudes and latencies in infants cannot be generalized across different types of speech stimuli and cannot be predicted from adult data. These findings also suggest that factors other than energetic masking are contributing to the immaturities in the SNR effects for infants. How these CAEP findings relate to an infant's capacity to process speech-in-noise perceptually has yet to be established; however, we can be confident that the presence of CAEPs to a speech stimulus in noise means that the stimulus is detected at the level of the auditory cortex. The absence of a response should be interpreted with caution as further studies are needed to investigate a range of different speech stimuli and SNRs, in conjunction with behavioral measures, to confirm that infant CAEPs do indeed reflect functional auditory capacity to process speech stimuli in noise.

How to study spoken language understanding: a survey of neuroscientific methods

ABSTRACTThe past 20 years have seen a methodological revolution in spoken language research. A diverse range of neuroscientific techniques are now available that allow researchers to observe the brain’s responses to different types of speech stimuli in both healthy and impaired listeners, and also to observe how individuals’ abilities to process speech change as a consequence of disrupting processing in specific brain regions. This special issue provides a tutorial review of the most important of these methods to guide researchers to make informed choices about which methods are best suited to addressing specific questions concerning the neuro-computational foundations of spoken language understanding. This introductory review provides (i) an historical overview of the experimental study of spoken language understanding, (ii) a summary of the key method currently being used by cognitive neuroscientists in this field, and (iii) thoughts on the likely future developments of these methods.

Effects of early home language environment on perception and production of speech

The effects of exposure to non-English heritage languages versus exposure to foreign-accented English during early childhood on language performances later in life were investigated. Three groups of young adult participants who differed in their early home language environment were examined on a series of linguistic tasks. Results showed that people who were mostly exposed to accented English in the early home environment are more native-like in various aspects of English language performance than those who were mostly exposed to their non-English heritage language, including vocabulary, pronunciation, and processing of certain types of speech stimuli. Early and extended exposure to accented speech, however, does not appear to enhance the ability to perceive foreign accents in general, and may in fact produce a disadvantage when listening to unfamiliar accents. These findings provide some initial insight into the consequences of migrant parents choosing to speak one language over the other with their children.

The Effect of Anchors and Training on the Reliability of Voice Quality Ratings for Different Types of Speech Stimuli

The main objective of the present study was to investigate if the type of voice stimuli-sustained vowel, oral reading, and connected speech-results in good intrarater and interrater agreement/reliability. A short-term panel study was performed. Voice samples from 30 native European Portuguese speakers were used in the present study. The speech materials used were (1) the sustained vowel /a/, (2) oral reading of the European Portuguese version of "The Story of Arthur the Rat," and (3) connected speech. After an extensive training with textual and auditory anchors, the judges were asked to rate the severity of dysphonic voice stimuli using the phonation dimensions G, R, and B from the GRBAS scale. The voice samples were judged 6 months and 1 year after the training. Intrarater agreement and reliability were generally very good for all the phonation dimensions and voice stimuli. The highest interrater reliability was obtained using the oral reading stimulus, particularly for phonation dimensions grade (G) and breathiness (B). Roughness (R) was the voice quality that was the most difficult to evaluate, leading to interrater unreliability in all voice quality ratings. Extensive training using textual and auditory anchors and the use of anchors during the voice evaluations appear to be good methods for auditory-perceptual evaluation of dysphonic voices. The best results of interrater reliability were obtained when the oral reading stimulus was used. Breathiness appears to be a voice quality that is easier to evaluate than roughness.

Children’s perception of their synthetically corrected speech production

We explore children’s perception of their own speech – in its online form, in its recorded form, and in synthetically modified forms. Children with phonological disorder (PD) and children with typical speech and language development (TD) performed tasks of evaluating accuracy of the different types of speech stimuli, either immediately after having produced the utterance or after a delay. In addition, they performed a task designed to assess their ability to detect synthetic modification. Both groups showed high performance in tasks involving evaluation of other children’s speech, whereas in tasks of evaluating one’s own speech, the children with PD were less accurate than their TD peers. The children with PD were less sensitive to misproductions in immediate conjunction with their production of an utterance, and more accurate after a delay. Within-category modification often passed undetected, indicating a satisfactory quality of the generated speech. Potential clinical benefits of using corrective re-synthesis are discussed.

Dysprosody and stimulus effects in Cantonese speakers with Parkinson's disease

Dysprosody is a common feature in speakers with hypokinetic dysarthria. However, speech prosody varies across different types of speech materials. This raises the question of what is the most appropriate speech material for the evaluation of dysprosody. To characterize the prosodic impairment in Cantonese speakers with hypokinetic dysarthria associated with Parkinson's disease, and to determine the effect of different types of speech stimuli on the perceptual rating of prosody. Speech data in the form of sentence reading, passage reading, and monologue were collected from ten Cantonese speakers with Parkinson's disease. Perceptual analysis was conducted on ten prosodic parameters to evaluate five dimensions of prosody, based on a theoretical framework: pitch, loudness, duration, voice quality, and degree of reduction. The results showed that the most severely affected prosodic parameters were monopitch, harsh voice, and monoloudness, followed by breathy voice and prolonged interval. Differences were noted between speakers with mild and moderate dysprosody. No statistically significant differences were found between the three types of stimuli. However, qualitative analysis revealed noticeable differences between the three stimuli in two speakers. The prosodic profile of Cantonese speakers with hypokinetic dysarthria is similar to those of other languages (for example, English). The involvement of two new dimensions in the definition of prosody (voice quality and degree of reduction) provides additional insight in differentiating patients with mild and moderate dysarthria. Further investigation on the use of speech materials in the clinical evaluation of speech prosody in speakers with dysarthria is needed, as no single task was found to represent a patient's performance under all circumstances.

Effect of dichotic listening on self-reported state anxiety

The present study examined the relationship between dichotic speech recognition and state anxiety. State anxiety, as determined by the State-Trait anxiety inventory (STAI), was measured pre- and post-dichotic testing in a group of young adults with normal hearing. Dichotic speech recognition was measured for three types of speech stimuli: 3-pair digits, monosyllabic words, and consonant-vowels. Results revealed significant increases in state anxiety as a function of dichotic testing for all stimulus types. There was not a significant difference, however, in state anxiety between the stimulus types. A subset of subjects (n=44) repeated the experiment a second time. There were no significant differences in state anxiety experienced due to dichotic listening between the two sessions. Results from the present study confirm that dichotic listening induces significant increases in state anxiety in a group of young adults with normal hearing. Although statistically significant, the mean increase in state anxiety does not exceed normative levels for college students. Further, the effect of anxiety on dichotic speech recognition performance appears minimal in this population.SumarioEl presente estudio examinó la relación entre el reconocimiento dicótico del lenguaje y los estados de ansiedad. El estado de ansiedad, determinado por el inventario estatal de rasgos de ansiedad (STAI), fue medido antes y después de las pruebas dicóticas en un grupo de adultos jóvenes con audición normal. El reconocimiento dicótico del lenguaje fue medido con tres tipos de estímulos lingüísticos: dígitos en 3 pares, monosilábicos dicóticos, y vocalesconsonantes. Los resultados revelaron aumentos significativos en el estado de ansiedad como una función de la evaluación dicóticos para todos los tipos de estímulos. No existió una diferencia significativa , sin embargo, en el estado de ansiedad entre los tipos de estímulos. Un subgrupo de sujetos (n = 44) repitió el experimento una segunda vez. No hubo diferencias significativas en el estado de ansiedad experimentado debido a la audición dicótica entre las dos sesiones. Los resultados del presente estudio confirman que la audición dicótica induce aumentos significativos en el estado de ansiedad en un grupo de adultos jóvenes con audición normal. Aunque resulte estadísticamente significativo, la media del incremento en el estado de ansiedad no excede los valores normativos para estudiantes universitarios. Más aún, el efecto de la ansiedad sobre el desempeño en el reconocimiento dicótico del lenguaje parece mínimo en esta población.

Effects of Speech Stimuli and Dysarthria Severity on Intelligibility Scores and Listener Confidence Ratings for Speakers with Cerebral Palsy

This study examined differences among transcription intelligibility scores and listener confidence ratings for three different types of speech stimuli – single words, unrelated sentences, and sentences forming a narrative – all produced by speakers with dysarthria. Twelve speakers with dysarthria of varying severity secondary to cerebral palsy and 144 listeners participated in this study. Results showed that both intelligibility scores and confidence ratings were differentially affected by both stimuli and severity. For speakers with mild, moderate, and severe dysarthria, intelligibility scores were higher for narratives than for either of the other two types of speech stimuli. For speakers with mild dysarthria, sentences were substantially more intelligible than single words. However, for speakers with moderate, severe, and profound dysarthria, the difference in intelligibility scores for sentences and single words was small or nonsignificant. Confidence ratings did not follow the same pattern as intelligibility data, suggesting a mismatch between listeners’ perception of their performance and their actual performance on intelligibility tasks.

Auditory Performance Characteristics of the Computerized Revised Token Test (CRTT)

To assess the Computerized Revised Token Test (CRTT) performance of individuals with normal hearing under several intensity conditions and under several spectral and temporal perturbation conditions. Sixty normal-hearing listeners were randomly assigned to 1 of 3 groups. Group 1 provided performance-intensity information about CRTT performance using uncompressed acoustic stimuli. Groups 2 and 3 completed the CRTT using temporally and spectrally compressed and expanded stimuli. CRTT performance functions were plotted for each group. Group 1 required minimal audibility to perform maximally on this task. As expected, Groups 2 and 3 showed significant differences across subtests, regardless of distortion condition. Mean differences in performance between successive conditions for Group 2 increased beyond 40% time compressed. There was 1 significant difference for the time-expanded condition. There were no differences across frequency compressed and expanded conditions. Young listeners require limited signal gain on the CRTT to achieve maximum performance. Time and frequency compression and expansion results were consistent with previous findings with varying types of speech stimuli. The results have implications for administration and interpretation of the CRTT administered to persons from other populations and will help in the development of a normative database for the CRTT.

Effect of Reading with Reversed Speech on Frequency of Stuttering in Adults

This study explored the effect of reading with reversed speech on the frequency of stuttering. Eight adults who stutter served as participants and read four 300-syllable passages while listening to three types of speech stimuli: normal speech (choral reading), reversed speech at normal speed, reversed speech at half speed, and a control condition of no auditory feedback. A repeated-measures analysis of variance showed a significant decrease in stuttering frequency in the choral reading condition but not in reversed speech at normal and half speed. However, the reversed speech at half-speed condition showed a large effect size (omega2 = 0.32). Data suggest that a forward moving speech feedback is not essential to decrease the frequency of stuttering in adults who stutter.

Cortical networks underlying audio-visual speech perception in normal-hearing and hearing impaired individuals

Functional magnetic resonance imaging (fMRI) was used to investigate the brain activity underlying audio-visual speech perception in normal-hearing and congenitally deaf individuals. Data were collected while subjects experienced three different types of speech stimuli: audio stimuli without visual input, video of a speaking face without audio input, and video of a speaking face with audio input. A control condition consisted of viewing a blank screen. The stimuli were vowels or CVCV syllables, presented in different blocks. Active brain regions for normal-hearing subjects during the visual-only condition included visual cortex, angular gyrus, fusiform gyrus, and auditory cortex, as well as premotor areas in the frontal cortex. The pattern of activation found for deaf subjects while viewing visual-only stimuli was similar to that of normal hearing subjects, but showed distinctly more activity in the right hemisphere (for both vowels and CVCVs), and far less activity in premotor and parietal cortex. Interestingly, the pattern of activity for deaf subjects in the visual-only case was found to be similar to normal-hearing subject activation in the audio-visual case. Finally, effective connectivity analyses were done to investigate connectivity between brain regions in the different conditions for both groups of subjects. [Research supported by NIDCD.]

Influence of encoding and acoustic similarity on the ear advantage and lag effect in dichotic listening.

Experiments with simultaneous and time lag dichotic listening conditions were used to test two hypotheses concerning the right ear advantage and lag effect in dichotic listening. One hypothesis is based on the similarity of acoustic spectra, and the other is based on a categorization of speech sounds as being either encoded or not encoded. Natural vowels and consonant-vowel syllables were used to obtain seven different types of speech stimuli: stop vowel syllables, fricative vowel syllables, stop burst noise, fricative noise, stop vowel transitions, fricative vowel transitions and steady state vowels. The presentation conditions were monaural, simultaneous dichotic, and dichotic with interaural time delays of 15, 30, 60, and 90 msec. With monaural presentations, all stimuli were identifiable above chance levels. For the simultaneous dichotic condition, significant right ear advantages occurred for stop vowel syllables, fricative vowel syllables, stop burst noise, and steady state vowels. For the time lag conditions, stop vowel syllables, stop bursts, and fricative noise produced consistent lag effects, but steady state vowels produced consistent lead effects. In general, the results gave stronger support to the hypothesis of acoustic similarity than to the encoding hypothesis in that stop burst noise produced both a right ear advantage and a lag effect whereas consonant-vowel transitions produced neither a right ear advantage nor a lag effect.

Spread-of-masking effects on pure tones and several speech stimuli.

A series of experiments was performed to study the upward-spread-of-masking phenomena as it pertains to pure-tone and speech stimuli. In the initial two experiments, three maskers were employed over a 40–60-dB intensity range. They included a wide band (50–5500 Hz), a speech spectrum (50–1000 Hz), and a narrow-band (50–950 Hz) noise. All filter slopes were 48 dB/octave, except for the upper slope of the speech-spectrum noise that was 6 dB/octave. In the first experiment, pure-tone thresholds obtained by a tracking procedure revealed no spread of masking when the wide-band and speech-spectrum maskers were used. Substantial spread-of-masking effects, characterized by nonlinear threshold increments outside the spectrum of the masker, were observed with the narrow-band masker. The second experiment included three types of speech stimuli (PBs, spondees, and synthetic sentences) under the same mask conditions used with the pure tones. Threshold shifts observed for the wide- and speech-spectrum maskers were linear with the masking intensity level. However, increased shifts, attributable to spread of masking, were observed with the narrow band and progressed nonlinearly as a function of the masking level. Finally, two additional experiments, performed with two different narrow-band maskers and spondee words, provided insightful information regarding the effects of the spread of masking on speech stimuli.