Influences of acculturation and musical sophistication on perception of musical interval patterns.

Influences of acculturation and musical sophistication on music perception were examined. Judgments for mistuning were obtained for Ss differing in musical sophistication who listened to a melody that was based on interval patterns from Western and Javanese musical scales. Less musically sophisticated Ss' judgments were better for Western than Javanese patterns. Musicians' thresholds did not differ across Western and Javanese patterns. Differences in judgments across scales are accountable to acculturation through listening exposure and musical sophistication gained through formal experience.

An event-based analysis of the coordination of early infant vocalizations and facial actions.

This study used an event-based approach to provide empirical evidence regarding the nature of coordination in 3- and 6-month-old infants. Vocalizations and facial actions of 12 normally developing infants interacting with their caregivers were coded. Coded vocalizations and facial actions were considered coordinated when they temporally overlapped. Results indicate that infants coordinated their vocalizations and facial actions more than expected by chance. Coordinated events were governed by 2 sequence patterns. When 2 communicative events were temporally associated across modalities, 1 event tended to be completely embedded within the other, and vocalizations tended to end before facial actions. This study provides new information about how infant communication is structured, confirms results from other coordination studies, and describes a new method for analysis of event-based data.

Late onset canonical babbling: a possible early marker of abnormal development.

By their 10th month of life, typically developing infants produce canonical babbling, which includes the well-formed syllables required for meaningful speech. Research suggests that emerging speech or language-related disorders might be associated with late onset of canonical babbling. Onset of canonical babbling was investigated for 1,536 high-risk infants, at about 10-months corrected age. Parental report by open-ended questionnaire was found to be an efficient method for ascertaining babbling status. Although delays were infrequent, they were often associated with genetic, neurological, anatomical, and/or physiological abnormalities. Over half the cases of late canonical babbling were not, at the time they were discovered associated with prior significant medical diagnoses. Late canonical-babbling onset may be a predictor of later developmental disabilities, including problems in speech, language, and reading.

FFT-based digital tactile vocoder system for real-time use.

A microprocessor-based real-time digital vibrotactile vocoder system has been developed to train the deaf and for artificial hearing research. The system is composed of a microcomputer module with a digital signal processor, interface units and an attenuator/driver circuit. Live or digitised (stored or synthetic) speech is presented to the skin spectrally through a belt housing eight or 16 vibrators. Speech is processed in real time using a fast Fourier transform. The system is also capable of presenting any arbitrary spatiotemporal pattern on the skin for artificial hearing experiments. A preliminary experiment with a deaf subject indicates that the system is potentially an effective device for artificial hearing.

Speech perception by congenitally deaf subjects using an electrocutaneous vocoder.

Two congenitally profoundly deaf adults were trained to perceive words through the Tacticon 1600 electrocutaneous vocoder, an artificial hearing prosthesis. The subjects learned to identify 50 words during 47 hours (Subject One) and 41 hours (Subject Two) of training, with a 41.6 percent rate of success across all sessions. Both subjects showed consistent error patterns during the training phase. Analysis of these error patterns suggested that they were employing word identification strategies based on some general aspects of tactual patterns. Specific characteristics of the tactual patterns that they appeared to be using included: syllable number, tactual locus of word ending, direction of pattern movement, and position of bursts (/t/, /k/, /d/, for example). Following training, the subjects were tested for their abilities to integrate tactual and aided-auditory cues in word identification. Three conditions of aided-audition alone (A), tactual vocoder alone (TV), and aided-audition with tactual vocoder (TV + A) were used. The stimulus-word list for this phase consisted of the 50 words acquired in tactual vocoder training, and 50 "tactually-new" words, i.e., words that had not been presented to them in tactual vocoder training sessions. They correctly identified 93 percent (Subject One) and 56 percent (Subject Two) more trials in the TV + A condition than in the A condition. Tactually-new vocabulary was correctly identified 78 percent (Subject One) and 50 percent (Subject Two) more often when sensory modalities were combined, than when only aided-audition was used. Subjects identified tactually-new vocabulary better than chance in the TV condition.

Assessment techniques to evaluate tactual aids for hearing-impaired subjects.

In order to optimize the use of tactual aids for the deaf, it is important to have a battery of assessments to determine the potential contribution of the aids to acoustic perception and speech identification. We have designed such a battery to be used with young hearing-impaired children. The tasks were developed so that they could be implemented with standard audiometric equipment and applied to subjects of varying age and to different types of tactual aids. Illustrative results from four profoundly hearing-impaired children showed that tactual vocoders allowed detection of high frequencies that were not available to the subjects through aided audition. In most cases with these subjects, performance on simple detection and discrimination tasks showed facilitative effects with tactual vocoders. Facilitative effects were further evidenced in more complex phonemic identification tasks for all subjects. The tasks can be used to determine possible benefits of tactual aids for individual hearing-impaired children.

The effects of vocoder filter configuration on tactual perception of speech.

Perception of synthetic speech continua through the sense of touch and audition was compared utilizing a 32-channel spectrally-oriented electrocutaneous vocoder display and standard auditory psychophysical procedures. Perception of a consonantal and a vocalic continuum was evaluated utilizing three vocoder filter configurations: logarithmic, linear, and average (geometric mean of logarithmic and linear). Results indicated a close correspondence between tactual and auditory discrimination and identification for the vowel (/a/-/e/) and the consonant (/sta/-/sa/) continuum regardless of the filter characteristics.

Classification of audiograms by sequential testing: reliability and validity of an automated behavioral hearing screening algorithm.

In 1990, CAST (classification of audiograms by sequential testing) was proposed and developed as an automated, innovative approach to screening infant hearing using a modified Bayesian method. The method generated a four-frequency audiogram in a minimal number of test trials using VRA (visual reinforcement audiometry) techniques. Computer simulations were used to explore the properties (efficiency and accuracy) of the paradigm. The current work is designed to further test the utility of the paradigm with human infants and young children. Accordingly, infants and children between 6 months and 2 years of age were screened for hearing loss. The algorithm's efficacy was studied with respect to validity and reliability. Validity was evaluated by comparing CAST results with tympanometric data and outcomes of staircase-based testing. Test-retest reliability was also assessed. Results indicate that CAST is a valid, efficient, reliable, and potentially cost-effective screening method.

Automated electrophysiologic hearing testing using a threshold-seeking algorithm.

The efficacy of utilizing an automated algorithm to identify auditory brainstem responses (ABR) was studied. A microcomputer-based threshold-seeking algorithm utilizing click-evoked ABR was developed to determine evoked-response thresholds for automated hearing screening. The software consists of an evoked-response recognizer unit, which determines the presence or absence of a response, and a threshold-tracking unit, which controls the click intensity in order to track the threshold. The response recognizer is based upon correlation methods. Threshold tracking is accomplished using a Parameter Estimation by Sequential Testing (PEST) procedure, which is commonly used to study psychophysical properties of the auditory system. Sound level is automatically adjusted, based on the results of the recognizer and the threshold tracker. Test results were generally obtained in less than 15 minutes per ear. The results of the automated procedure correlate very highly with expert judgments of ABR threshold and show good test-retest reliability, suggesting that automated procedures are viable alternatives to traditional testing methods.

Precursors to speech in infancy: the prediction of speech and language disorders.

During the canonical stage of infant babbling, infants produce well-formed syllables, often in reduplicated sequences such as "bababa." Although nearly all infants with normal hearing begin the canonical stage by 10 months of age, a few are delayed, and these infants may be of special interest. Recent studies indicate that late onset of canonical babbling may be a predictor of disorders. A simple screening procedure that focuses on canonical babbling was used to evaluate over 3400 infants at risk who were about 10 months of age. Among infants who showed late onset of canonical babbling, fewer than half had been previously diagnosed as having a significant medical problem that might have accounted for the delay. A follow-up study indicated that infants with delayed canonical babbling had smaller production vocabularies at 18, 24, and 30 months than did infants in the control group. The results suggest that late onset of canonical babbling, a factor that can be monitored effectively through an interview with a parent, can predict delay in the onset of speech production.

Dermatologic infections in cancer patients treated with epidermal growth factor receptor inhibitor therapy.

BACKGROUND: Patients treated with epidermal growth factor receptor inhibitors (EGFRIs) frequently experience dermatologic toxic effects. Whereas the impact of these effects on quality of life and EGFRI dosing has been described, their impact on physical health has not been ascertained. We examined the prevalence of infections that complicate dermatologic toxic effects of EGFRIs. METHODS: We used retrospective chart review methods to analyze 221 patients who were treated in the Skin and Eye Reactions to Inhibitors of EGFR and Kinases clinic, a referral clinic for dermatologic toxic effects of cancer therapies. We reviewed results of bacterial cultures, histopathologic assessment of biopsy samples, and immunohistochemical staining of skin specimens for viral pathogens that were recorded in the patients' medical records. Associations between patient demographic and treatment characteristics and the development of infections were examined using the Fisher exact test. All statistical tests were two-sided. RESULTS: Eighty-four (38%) of the 221 patients showed evidence of infection at sites of dermatologic toxic effect. Fifty (22.6%) of the 221 patients had cultures positive for Staphylococcus aureus, and 12 (5.4%) of the 221 patients cultured positive for methicillin-resistant S aureus. Less frequent infections included herpes simplex (3.2%), herpes zoster (1.8%), and dermatophytes (10.4%). The seborrheic region was the most prevalent site of infection, and patients with leukopenia had higher risk for infection than patients who did not have leukopenia (P = .005). Demographic factors and associated treatments were not associated with the occurrence of a dermatologic infection (P > or = .05). CONCLUSIONS: Patients with dermatologic toxic effects following treatment with EGFRIs have a high prevalence of cutaneous infections. Most notably, bacterial infections developed at sites previously affected by dermatologic toxic effects, with leukopenic patients being at greater risk.

A study of perceptual development for musical tuning.

Musical tuning perception in infancy and adulthood was explored in three experiments. In Experiment 1, Western adults were tested in detection of randomly located mistunings in a melody based on musical interval patterns from native and nonnative musical scales. Subjects performed better in a Western major scale context than in either a Western augmented or a Javanese pelog scale context. Because the major scale is used frequently in Western music and, therefore, is more perceptually familiar than either the augmented scale or the pelog scale are, the adults' pattern of performance is suggestive of musical acculturation. Experiments 2 and 3 were designed to explore the onset of culturally specific perceptual reorganization for music in the age period that has been found to be important in linguistically specific perceptual reorganization for speech. In Experiment 2, 1-year-olds had a pattern of performance similar to that of the adults, but 6-month-olds could not detect mistunings reliably better than chance. In Experiment 3, another group of 6-month-olds was tested, and a larger degree of mistuning was used so that floor effects might be avoided. These 6-month-olds performed better in the major and augmented scale contexts than in the pelog context, without a reliable performance difference between the major and augmented contexts. Comparison of the results obtained with 6-month-olds and 1-year-olds suggests that culturally specific perceptual reorganization for musical tuning begins to affect perception between these ages, but the 6-month-olds' pattern of results considered alone is not as clear. The 6-month-olds' better performance on the major and augmented interval patterns than on the pelog interval pattern is potentially attributable to either the 6-month-olds' lesser perceptual acculturation than that of the 1-year-olds or perhaps to an innate predisposition for processing of music based on a single fundamental interval, in this case the semitone.

A comparative study of speech perception in young severely retarded children and normally developing infants.

The discrimination of minimally paired speech sounds by seven retarded children with a mean age of 3 years, 2 months and a mean IQ of 38.4 was compared with the discrimination performance of eight normally developing 7-month-old infants. Children and infants were tested using the Visually Reinforced Infant Speech Discrimination (VRISD) paradigm in which they were taught to respond with a head turn to a change in a repeating background auditory stimulus. Responses were reinforced by activation of an animated toy. All children proved to be conditionable and both groups evidenced discrimination of the speech contrasts tested. The data suggest that the retarded children have moree difficulty processing a contrast cued by rapid spectral changes (often associated with consonant discrimination) than they do a contrast cued by steady-state spectral information (often associated with the perception of slowly articulated vowels). The normally developing infants did not find rapid spectral cues mor difficult than steady-state cues These results parallel those of Tallal (1976) who found that dynamic cues were specifically difficult for dysphasic children (with normal nonverbal intelligence), but not for linguistically-normal elementary school children.

Infant vocalizations and the early diagnosis of severe hearing impairment.

To determine whether late onset of canonical babbling could be used as a criterion to determine risk of hearing impairment, we obtained vocalization samples longitudinally from 94 infants with normal hearing and 37 infants with severe to profound hearing impairment. Parents were instructed to report the onset of canonical babbling (the production of well-formed syllables such as "da," "na," "bee," "yaya"). Verification that the infants were producing canonical syllables was collected in laboratory audio recordings. Infants with normal hearing produced canonical vocalizations before 11 months of age (range, 3 to 10 months; mode, 7 months); infants who were deaf failed to produce canonical syllables until 11 months of age or older, often well into the third year of life (range, 11 to 49 months; mode, 24 months). The correlation between age at onset of the canonical stage and age at auditory amplification was 0.68, indicating that early identification and fitting of hearing aids is of significant benefit to infants learning language. The fact that there is no overlap in the distribution of the onset of canonical babbling between infants with normal hearing and infants with hearing impairment means that the failure of otherwise healthy infants to produce canonical syllables before 11 months of age should be considered a serious risk factor for hearing impairment and, when observed, should result in immediate referral for audiologic evaluation.

Fricative discrimination in early infancy.

In three separate experiments using controlled natural stimuli and a high-amplitude sucking paradigm, infants' ability to detect differences between /s/ and /v/, /s/ and /f/, and /s/ and /z/, respectively, was investigated. Evidence for discrimination was obtained for /s/ versus /v/ and /s/ versus /f/ but not for /s/ versus /z/. Implications for a theory of infant speech perception are discussed.

Speech identification in Spanish- and English-learning 2-year-olds.

English- and Spanish-learning 2-year-olds were tested for speech skills in a real speech context. Each child was tested in his/her native language on one native and one nonnative contrast. The nonnative contrast consisted of a real native word paired with a nonsense word containing a nonnative element. The native contrast consisted of a native word paired with a nonsense word containing a minimally paired native element. The results showed that both groups of children found identification of native contrasts much easier than identification of nonnative contrasts. The results suggest that by age 2, normal children may have achieved an awareness of their native phonology, an awareness that encourages them to ignore certain distinctions that are not part of their language's contrastive meaning system.

The role of audition in infant babbling.

The traditional belief that audition plays only a minor role in infant vocal development depends upon evidence that deaf infants produce the same kinds of babbling sounds as hearing infants. Evidence in support of this position has been very limited. A more extensive comparison of vocal development in deaf and hearing infants indicates that the traditional belief is in error. Well-formed syllable production is established in the first 10 months of life by hearing infants but not by deaf infants, indicating that audition plays an important role in vocal development. The difference between babbling in the deaf and hearing is apparent if infant vocal sounds are observed from a metaphonological perspective, a view that takes account of the articulatory/acoustic patterns of speech sounds in all mature spoken languages.

Developmental changes in speech discrimination in infants.

A visually reinforced infant speech discrimination (VRISD) paradigm is described and evaluated. Infants at two ages were tested with the new paradigm on the following speech contrasts: [sa] vs [va], [sa] vs [fa], [sa] VS [za], [as] vs [a:s], vs [a:z], [at] vs [a:d], [a:t] vs [a:d], [at] vs [a:t], [fa] vs [thetaa]and [fi] vs [thetai]. The data reported are compared with data on the same speech contrasts obtained from three month olds in a high-amplitude sucking paradigm. Evidence suggesting developmental changes in speech-sound discriminatory ability is reported. Results are interpreted in light of salience of available acoustic cues and in terms of new methodological advances.

Effects of early linguistic experience on speech discrimination by infants: a reply.

This paper is a reply to a critique of Eilers, Gavin, and Wilson (1979) by Aslin and Pisoni (this issue). The reply argues that the critics' contentions are basically unwarranted on both methodological and conceptual grounds. The critique is largely based on misunderstandings of the study's purposes and procedures.