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PubMed1993

Chronic otitis media and early speech development: a case study.

A case study of the speech development in a male infant with chronic otitis media is reported. The phonetic behavior characterizing the child's vocalizations was sampled monthly between the ages of 11 and 21 months, as he progressed from pre-speech to early speech periods of language development. Results of monthly phonetic inventory analyses indicated age-appropriate types of consonants in his pre-word and later-word vocalizations. However, the child's repertoire of consonants was considerably reduced as he first began to produce meaningful speech. Results of phonetic diversity analyses revealed an overall lack of phonetic complexity in his vocalizations throughout the course of study. In general, the child's early sound productions were characteristic of developmental delay, closely resembling the speech patterns found among severely hearing-imparied children. Findings are discussed with respect to the probable influence of chronic otitis media with effusion on a child's eventual speech development.

Chronic Disease↗

PubMed2005

Processing of audiovisual speech in Broca's area.

We investigated cerebral processing of audiovisual speech stimuli in humans using functional magnetic resonance imaging (fMRI). Ten healthy volunteers were scanned with a 'clustered volume acquisition' paradigm at 3 T during observation of phonetically matching (e.g., visual and acoustic /y/) and conflicting (e.g., visual /a/ and acoustic /y/) audiovisual vowels. Both stimuli activated the sensory-specific auditory and visual cortices, along with the superior temporal, inferior frontal (Broca's area), premotor, and visual-parietal regions bilaterally. Phonetically conflicting vowels, contrasted with matching ones, specifically increased activity in Broca's area. Activity during phonetically matching stimuli, contrasted with conflicting ones, was not enhanced in any brain region. We suggest that the increased activity in Broca's area reflects processing of conflicting visual and acoustic phonetic inputs in partly disparate neuron populations. On the other hand, matching acoustic and visual inputs would converge on the same neurons.

Adult↗

PubMedDate not supplied

Voice and speech after laryngectomy.

The aim of the investigation is to compare voice and speech quality in alaryngeal patients using esophageal speech (ESOP, eight subjects), electroacoustical speech aid (EACA, six subjects) and tracheoesophageal voice prosthesis (TEVP, three subjects). The subjects reading a short story were recorded in the sound-proof booth and the speech samples were acoustically analysed. Speech sound production was judged by 15 students of phonetics. The following variables were considered: (1) voice quality: fo, jitter, shimmer and harmonic-to-noise ratio, (2) speech sound production: number of recognized VCV syllables, and (3) temporal organization of speech: duration of the phonetic block, number of syllables in the phonetic block, rate of speech, rate of articulation and number of syllables in the longest phonetic block. The results showed that nearly normal air-stream source (lungs) in speech production of speakers with tracheoesophageal prosthesis significantly contributed to the speech timing and speech intelligibility of the alaryngeal speakers.

Aged↗

PubMedDate not supplied

Real-time language processing in school-age children with specific language impairment.

BACKGROUND: School-age children with specific language impairment (SLI) exhibit slower real-time (i.e. immediate) language processing relative to same-age peers and younger, language-matched peers. Results of the few studies that have been done seem to indicate that the slower language processing of children with SLI is due to inefficient higher-order linguistic processing and not to difficulties with more basic acoustic-phonetic processing. However, this claim requires further experimental verification. AIMS: It was investigated whether the real-time language processing deficit of children with SLI arises from inferior acoustic-phonetic processing, inefficient linguistic processing, or both poor sensory processing and linguistic processing. If these children's impaired online language processing is due to inferior acoustic-phonetic processing, then their reaction time (RT) for recognizing words presented in list fashion should be significantly longer relative to control children's RT. If, however, their impaired language processing relates to inefficient linguistic processing, then, relative to control children, their RT for word-list-presented words should be comparable and their sentence-embedded word-recognition RT should be significantly longer. METHODS & PROCEDURES: Sixteen school-age children with SLI, 16 age-matched (CA) typically developing children, and 16 receptive-syntax matched (RS) children completed two word-recognition RT tasks. In one task, children monitored word lists for the occurrence of a target word (isolated lexical processing task). In the second task, children monitored simple sentences for a target word (sentence-embedded lexical processing task). In both tasks, children made a timed response immediately upon recognizing the target. OUTCOMES & RESULTS: Children with SLI and CA children showed comparable RT in the isolated lexical processing task and both were faster than RS children. In the sentence-processing task, children with SLI were slower at lexical processing than CA and RS children, with CA children demonstrating the fastest processing. CONCLUSIONS: The real-time language processing of children with SLI appears to be attributable to inefficient higher-order linguistic processing operations and not to inferior acoustic-phonetic processing. The slower language processing of children with SLI relative to younger, language-matched children suggests that the language mechanism of children with SLI operates more slowly than what might otherwise be predicted by their linguistic competence.

Analysis of Variance↗

PubMed1994

Impairments of speech production and speech perception in aphasia.

The basis of speech production and speech perception deficits in aphasia relates to implementation and access rather than to the underlying representation or knowledge base of the sound structure of language. Speech production deficits occur on the phonological level in which the incorrect phonological form of the word is selected but is implemented correctly, and the phonetic level in which the correct sound segments are selected but articulatory implementation is impaired. Phonological deficits emerge regardless of lesion site, whereas phonetic deficits have a specific localized neuroanatomical substrate. Phonetic deficits are not linguistic but affect particular articulatory movements. Speech perception impairments emerge in nearly all aphasic patients, suggesting that the neural basis for speech perception is broadly distributed in the language hemisphere. The impairment reflects the misperception of phonetic features rather than a deficit in the auditory processing of speech and emerges particularly as the sound properties of speech contact the lexicon.

Aphasia↗

PubMedDate not supplied

Properties of school Chinese: implications for learning to read.

The properties of the 2,570 Chinese characters explicitly taught in Chinese elementary schools were systematically investigated, including types of characters, visual complexity, spatial structure, phonetic regularity and consistency, semantic transparency, independent and bound components, and phonetic and semantic families. Among the findings are that the visual complexity, phonetic regularity, and semantic transparency of the Chinese characters taught in elementary school increase from the early grades to the later grades: Characters introduced in the 1st or 2nd grade typically contain fewer strokes, but are less likely to be regular or transparent, than characters introduced in the 5th or 6th grade. The inverse relation holds when characters are stratified by frequency. Low-frequency characters tend to be visually complex, phonetically regular, and semantically transparent whereas high-frequency characters tend to be the opposite. Combined with other findings, the analysis suggests that written Chinese has a logic that children can understand and use.

Child↗

PubMed1985

Perceptual equivalence of acoustic cues that differentiate /r/ and /l/.

The perceptual effects of orthogonal variations in two acoustic parameters which differentiate American English prevocalic /r/ and /l/ were examined. A spectral cue (frequency onset and transition of F2 and F3) and a temporal cue (relative duration of initial steady state and transition of F1) were varied in synthetic versions of "rock" and "lock." Four temporal variations in each of ten stimuli of a spectral-cue continuum were generated. Phonetic identification and oddity discrimination tasks with the four series showed systematic displacement of perceptual boundaries and discrimination peaks, thus reflecting a trading relation between the two cues. The perceptual equivalence of spectral and temporal cues was investigated by comparing the accuracy of discrimination of three types of stimulus comparisons: phonetically facilitating two-cue pairs, one-cue pairs, and phonetically conflicting two-cue pairs. As predicted, discrimination accuracy was ordered: Facilitating cues greater than one-cue greater than conflicting cues, indicating that perceivers discriminated on the basis of an integrated phonetic percept.

Acoustic Stimulation↗

PubMed2002

Underlying mechanism for categorical perception: tone-onset time and voice-onset time evidence of Hebrew voicing.

The nature of the mechanism responsible for the categorical labeling of stimuli is not clear. One hypothesis suggests that categorization is limited by the 'natural sensitivities' of the auditory system. The alternative hypothesis suggests that categorization is mediated by a special speech mode and is influenced by how speech is produced. The present study attempts to provide some insight into this dilemma by evaluating categorical perception (CP) in speech and non-speech stimuli and across languages. Specifically, the goals of the present study were (1) to compare phonetic boundaries of Hebrew voicing to categorical boundaries (CB) of a two-tone complex which varies in the relative timing of the two tones (TOT) [TOT stimuli are considered be the non-speech analog to voice-onset time (VOT)], and (2) to re-establish the CB values of non-speech analog to voicing in American-English speakers using the same TOT continua as the Hebrew speakers and to compare them to CB of Hebrew-speaking subjects. Our assumption was that if CP is mediated by basic auditory sensitivity then we expect similar CB for speech and non-speech stimuli and no effect of language on CB. If, however, a special speech code determines CP, then phonetic boundaries are expected to be different from CB of non-speech stimuli and across languages. Of particular interest is the special case of Hebrew whose voice-voiceless distinction in production is very different from that in English. Twelve Hebrew-speaking adults and 12 American-English speaking adults participated in this study. Stimuli consisted of (a) a two-tone complex continuum that varied in the relative onset time of the lower tone from a lead of -100 ms to a lag of +50 ms in 10 ms steps, and (b) a /ba-pa/ continuum which varied in VOT values similar to (a). Subjects identified TOT stimuli as belonging to one of three categories: leading, simultaneous, or lagging. VOT stimuli were labeled as /ba/ or /pa/. Results show (a) different phonetic boundary for Hebrew voicing compared to published data on English voicing, (b) different category boundaries for speech and non-speech stimuli in Hebrew, (c) a phonetic boundary for Hebrew voicing that does not align with the VOT values of production, and (d) very similar CB for TOT stimuli in Hebrew- and American-English-speaking subjects. The data support the influence of both general auditory abilities and unique speech processes on categorical perception of speech.

Acoustic Stimulation↗

PubMed2006

[Morphology of the glottis after supracricoid laryngectomy with CHP or CHEP and restoration of basic laryngeal function with special attention to quality of phonation].

PURPOSE: The aim of this work was to describe the morphology of the reconstructed larynx after supracricoid horizontal laryngectomy with simultaneous cricohyopexy (CHP) or cricohyoepiglottopexy (CEHP) preserving one or both arytenoid cartilages, to study the protective and respiratory functions of the larynx, to perform phoniatric evaluation of phonation quality, to analyze voice and speech phonetic-acoustic parameters, and to search for correlations between reconstruction type and phonetic-acoustic characteristics of voice and speech. MATERIAL AND METHODS: The material comprised 58 patients (32 after CHP and 26 after CHEP). CONCLUSION: Oval shape of the neoglottis dominated. Swallowing was normal in 46% of patients and did not depend on reconstruction type. Decannulation was possible in 66% of patients. The results were inferior after CHEP with both arytenoid cartilages intact. Socially efficient speech was found in 74% of patients and the results were better with CHEP. The phonetic-acoustic structure of voice and resonant speech was considerably different from the phonetic-acoustic structure of voice and speech under physiologic conditions. These differences applied to segmental (formant structure frequencies, noise range), as well as suprasegmental voice features.

Adult↗

PubMed1993

An investigation of attention allocation deficits in aphasia.

Nine aphasic and 18 normal adults participated in a dual task with components of phoneme monitoring and semantic judgment. Subjects listened to lists of recorded spoken words and were required to detect semantic and phonetic targets. Two within-subject variables were manipulated: the probability of target occurrence for each dual-task component (.2, .5, and .8) and the explicitness of instruction (explicit vs. implicit). Only in the explicit condition were subjects told about the probability structure and given the attention allocation strategy congruent with that structure. Reaction times were recorded on-line for analysis by an IBM-AT. The results showed that normal subjects' overall latencies in detecting phonetic targets decreased as the target occurrence probability increased in both implicit and explicit instruction conditions. The detection latencies for semantic targets showed a similar probability effect but only in the explicit condition. By contrast, the aphasic subjects did not show the probability effect in any condition, although they performed above the chance level on both semantic and phonetic tasks. The presence of the probability effects for the normal subjects indicated that an efficient attention allocation mechanism was operating so as to optimize the performance level. On the other hand, the absence of probability effects for the aphasic subjects suggests that their attention control system might be inefficient so that task-demand cues (probability and attention allocation instruction) were not utilized properly.

Adult↗

PubMed1995

Physiologic correlates of the voice onset time boundary in primary auditory cortex (A1) of the awake monkey: temporal response patterns.

Behavioral studies in animals support the view that categorical, phonetic phenomena are based upon specific response properties of the auditory system. This study investigated physiologic responses reflecting the phonetic parameter of voice onset time (VOT). We examined multiunit activity (MUA) in the primary auditory cortex (A1) of awake monkeys elicited by the consonant-vowel syllables /da/ and /ta/ that varied in VOT from 0 to 60 msec. Two temporal response patterns encode VOT. The first pattern contains responses time-locked to stimulus onset and to the onset of voicing. In 10 of 17 electrode penetrations that display this pattern, MUA reflects the VOT perceptual boundary by containing a prominent response to voicing onset only for /ta/ stimuli. The second pattern contains responses phase-locked to the periodic portion of the syllables. MUA exhibiting this temporal pattern does not display categorical-like properties. We conclude that specific temporal response patterns in A1 reflect the perceptual boundary for VOT and may represent a physiologic correlate for categorical perception of this phonetic parameter.

Animals↗

PubMed1995

EEG power spectra of dysphonetic and nondysphonetic poor readers.

Two subtypes of poor readers, dysphonetic and phonetic, were compared on EEG spectral values obtained as they viewed strings of letters and short words. Dysphonetic poor readers had significantly higher values than phonetics in the theta and delta bands. Both phonetic and dysphonetic poor readers had lower beta values than adequate reading children with Attention Deficit Disorder. This evidence indicates that poor readers, especially dysphonetics, were less actively engaged in the task.

Achievement↗

PubMed1998

Consonant and vowel production of right hemisphere patients.

Recent reports of subclinical phonetic deficits in posterior and most particularly in Wernicke's aphasics have challenged the traditional dichotomy which characterized speech deficits in aphasia as anterior/phonetic and posterior/phonological. It is unclear whether the basis of the phonetic deficit in posterior aphasics reflects the fact that the speech production system extends to more posterior regions of the left hemisphere than previously thought or alternatively is the result of generalized brain damage effects. The present study explores the latter possibility by investigating the patterns of speech production in right hemisphere brain-damaged, non-aphasic patients with anterior and posterior lesions. Acoustic analyses conducted on a range of consonant and vowel parameters showed differences between the speech patterns of both anterior and posterior right hemisphere patients and that of Wernicke's aphasics. These findings suggest that the subclinical deficit of Wernicke's aphasics can not simply be ascribed to a generalized brain-damage effect and raise the possibility that the right hemisphere also plays some role, if only a minor one, in the phonetic implementation of speech.

Aged↗

PubMed2002

Human cortical dynamics determined by speech fundamental frequency.

Evidence for speech-specific brain processes has been searched for through the manipulation of formant frequencies which mediate phonetic content and which are, in evolutionary terms, relatively "new" aspects of speech. Here we used whole-head magnetoencephalography and advanced stimulus reproduction methodology to examine the contribution of the fundamental frequency F0 and its harmonic integer multiples in cortical processing. The subjects were presented with a vowel, a frequency-matched counterpart of the vowel lacking in phonetic contents, and a pure tone. The F0 of the stimuli was set at that of a typical male (i.e., 100 Hz), female (200 Hz), or infant (270 Hz) speaker. We found that speech sounds, both with and without phonetic content, elicited the N1m response in human auditory cortex at a constant latency of 120 ms, whereas pure tones matching the speech sounds in frequency, intensity, and duration gave rise to N1m responses whose latency varied between 120 and 160 ms. Thus, it seems that the fundamental frequency F0 and its harmonics determine the temporal dynamics of speech processing in human auditory cortex and that speech specificity arises out of cortical sensitivity to the complex acoustic structure determined by the human sound production apparatus.

Adult↗

PubMed1991

Phonological deficits: beneath the surface of reading-acquisition problems.

In Experiment 1, the performance of young retarded readers on speech-segmentation tasks was compared with the performance of normal subjects matched for chronological age (CA) and with subjects matched for reading age (RA). Retarded readers were poorer than both control groups in consonant deletion, while there was no difference between the groups on a rhyme-judgement task and a syllabic-vowel-reproduction task. In Experiment 2, another group of reading retarded children was compared with CA and RA controls on the classification of pseudo-words, either by common phoneme or by overall phonetic similarity. The retarded readers made fewer classifications based on common phoneme than both control groups, while there was no difference between the groups in classifications based on overall phonetic similarity. In Experiment 3, adult developmental dyslexics were compared with normal adults in the tasks of Experiments 1 and 2. The dyslexics made fewer classifications based on a common phoneme than the normals, while no difference was found in classifications based on overall phonetic similarity.

Adolescent↗

PubMed1989

Reading, spelling, and vigilance in attention deficit and conduct disorder.

A group of 51 male children, average age 9.1 years, presenting at a child psychiatric clinic because of attention and conduct problems were investigated for reading and phonetic spelling ability, vigilance, and intellectual level. Each child was given a DSM-III diagnosis prior to being tested. The Boder Test of Reading and Spelling patterns was used to obtain scores for reading age, number of syllables read correctly in the word list at the child's reading level, and number of phonetically correct syllables spelled in the known and unknown word lists, at and just above the child's reading level. A factor analysis with varimax rotation produced two significant factors, a Reading factor with high loadings for verbal and reading scores, aand a second Vigilance factor. Phonetic spelling ability loaded separately from reading into the Vigilance factor. The Vigilance factor was significantly related to the diagnosis of moderate and severe attention deficit disorder with hyperactivity (ADDH). The correlation of short-term working memory with vigilance in moderate to severe ADDH children is discussed.

Achievement↗

PubMed1988

Reduced P3 amplitude of the event-related brain potential: its relationship to language ability in autism.

Several studies have found that P3 amplitude of the auditory event-related potential is smaller in autistic than in normal children. The present study investigated whether this characteristic bears any relationship to the degree of language impairment and/or level of intellectual ability of autistic persons. Seventeen autistic children, ranging from 8-19 years of age, and 17 age- and gender-matched normal children participated. Event-related potentials to phonetic ("Da") and chord (piano) stimuli were recorded from three scalp locations: vertex (Cz), right hemisphere (RH), and left hemisphere (LH), during a discrimination task. A battery of language tests was given to autistic children. Compared to normal subjects, autistic subjects showed a significantly smaller P3 amplitude to phonetic stimuli for Cz and LH recording sites. However, no group difference in P3 amplitude to the phonetic stimulus was found for the RH. Furthermore, no group differences in P3 amplitude were found for the chord stimulus at any recording site. Impaired language ability was related to greater RH P3 amplitude, particularly to the chord stimulus. The possibility of differential hemispheric involvement in the attentional deficits of autistic children is raised.

Adolescent↗

PubMed2007

Intonation and emotion in autistic spectrum disorders.

The classic picture of an autistic individual includes an impoverished ability to interpret or express emotion. The prosody of spoken language in autistic children is thought to lack emotional content. In this study, the verbal intonation of children with autism was examined and compared to that of children with Asperger Syndrome (AS) and normal controls (ctrl). Utterances elicited by repetition and by spontaneous story completion were analyzed by quantifying phonetic features (pitch, amplitude, and length) and comparing them to subjective ratings of produced emotion (happy, sad or angry). Since the most consistent phonetic correlate of these emotional targets has been demonstrated to be pitch range, speakers with autistic spectrum disorders were expected to have decreased pitch range; however in the repetition task, autistic subjects actually had a larger pitch range than the other groups. Other measures of intonation including amplitude, duration, and location of pitch peak revealed defects that are more complex than predicted. In spontaneous speech, autistic subjects performed more poorly on both phonetic targets and subjective ratings than ctrls, and AS subjects fell between autistics and normals.

Adolescent↗