Laura Schulte

A comparison of transient‐evoked and distortion product otoacoustic emissions in normal‐hearing and hearing‐impaired subjects

The ability of transient-evoked otoacoustic emissions (TEOAEs) and distortion product otoacoustic emissions (DPOAEs) to distinguish normal hearing from hearing impairment was evaluated in 180 subjects. TEOAEs were analyzed into octave or one-third octave bands for frequencies ranging from 500 to 4000 Hz. Decision theory was used to generate receiver operating characteristic (ROC) curves for each of three measurements (OAE amplitude, OAE/noise, reproducibility) for each OAE measure (octave TEOAEs, 1/3 octave TEOAEs, DPOAEs), for octave frequencies from 500 to 4000 Hz, and for seven audiometric criteria ranging from 10 to 40 dB HL. At 500 Hz, TEOAEs and DPOAEs were unable to separate normal from impaired ears. At 1000 Hz, both TEOAE measures were more accurate in identifying hearing status than DPOAEs. At 2000 Hz, all OAE measures performed equally well. At 4000 Hz, DPOAEs were better able to distinguish normal from impaired ears. Almost without exception, measurements of OAE/noise and reproducibility performed comparably and were superior to measurements of OAE amplitude, although the differences were small. TEOAEs analyzed into octave bands showed better performance than TEOAEs analyzed into 1/3 octaves. Under standard test conditions, OAE test performance appears to be limited by background noise, especially for the low frequencies.

Patterns of physical and sexual abuse of communicatively handicapped children

Evidence suggests that handicapped children are at increased risk for abuse and neglect. Communicatively impaired youngsters are particularly vulnerable because of their limited ability to report the maltreatment. Of 482 abused handicapped children evaluated at Boys Town National Research Hospital, 212 had hearing impairment, 87 speech language disorders, 39 learning disorders, 43 behavioral-emotional disturbances, 74 mental retardation, 5 visual impairment, 3 cleft lip or palate, and 19 other disorders. The perpetrator was either a relative or a “trusted other” in 97.2% of sexual abuse cases. Handicapped males were much more likely to be victims of sexual abuse than nonhandicapped males in the general population. Children being educated in residential schools were more likely to be sexually abused than mainstreamed youngsters. These children may be at risk for abuse from a wide variety of potential perpetrators, including teachers, dormitory counselors, van drivers, clergy, classroom aides, older students, peer siblings, scout leaders, abused peers, baby-sitters, and custodians.

Basic characteristics of distortion product otoacoustic emissions in infants and children

Distortion-product otoacoustic emissions at the 2 f1-f2 frequency (DPOAEs) are being advocated as a clinical tool for diagnosis of peripheral auditory pathology. Because they can be measured quickly and noninvasively, they may be an excellent method for identifying hearing loss in infants and children. However, few studies have examined the characteristics of DPOAEs in infants and children or detailed if, and how, their responses differ from those of adults. The purpose of the current study was to determine basic characteristics of DPOAEs in infants, toddlers, children, and young adults and to define any differences among age groups. An additional goal was to ensure that the presence of spontaneous otoacoustic emissions (SOAEs) did not confound any developmental effect. DPOAE input/output (I/O) functions at seven f2 frequencies and SOAEs were measured from one ear of 196 subjects. Children aged less than 1 yr had significantly higher mean DPOAE levels than older children and adults, and children aged 1-3 yr had higher mean DPOAE levels than teens and adults. These differences were dependent on frequency but were independent of f2 level and SOAE status. At every f2 frequency, groups of individuals having SOAEs had higher mean DPOAE levels than those not having SOAEs.

Basic characteristics of click-evoked otoacoustic emissions in infants and children

Since Kemp [J. Acoust. Soc. Am. 64, 1386-1391 (1978)] first described click-evoked otoacoustic emissions (COAEs), researchers have advocated their use as an excellent tool for diagnosing hearing loss in infants and children. However, there are few detailed reports of COAEs in this population, and those that do exist suggest that there are age-dependent differences. The purpose of the current study was to determine basic characteristics of COAEs in infants, toddlers, children, and young adults and to define any differences among age groups. An additional goal was to ensure that spontaneous otoacoustic emissions (SOAEs) did not confound any possible developmental effects. COAEs and SOAEs were measured from one ear of 223 normal-hearing subjects. COAE input/ output functions indicated that children aged less than one year have higher COAE levels than older children and adults. Children aged 1-5 yr had higher COAE levels than those aged 12-17 yr and adults. These differences were independent of level and SOAE status, but were dependent on frequency. The results of this study suggest that different clinical norms may be necessary for children aged less than 6 years.

Longitudinal changes in children's speech and voice physiology after cochlear implantation.

Objectives The purposes of this investigation were 1) to describe speech/voice physiological characteristics of prelingually deafened children before and after cochlear implantation and determine whether they fall into a range that would be considered deviant, 2) to determine whether selected deviant articulatory and phonatory behaviors of children with cochlear implants persist despite long-term cochlear implant use and continued participation in aural rehabilitation services, and 3) to determine whether further development of deviant articulatory and phonatory behaviors occurs postimplantation. Design Seven prelingually deafened children who received cochlear implants after 5 yr of age were followed from shortly before implantation until 5 to 6 yr postimplantation. These children received their early education in a Total Communication environment and used the Nucleus 22-electrode cochlear implant. All of them initially used the MPEAK speech processing strategy, and five of them eventually upgraded to the SPEAK speech processing strategy. Speech/voice physiological measurements that were obtained periodically from the children included intraoral air pressure (Po), nasal and phonatory air flow, voice onset time (VOT), and fundamental frequency (Fo). Data from the deaf children were compared with a database from 56 children with normal hearing to determine when the deaf children exhibited “deviant” speech/voice behaviors. Speech/voice behaviors were considered “deviant” if they never occurred for children with normal hearing or were associated with z-scores that were outside the range of ±2.0. Results The deaf children showed a wide range of deviant speech and voice behaviors both pre- and post-cochlear implant. The most frequently occurring atypical behaviors were use of negative Po, high Po for [b, m], long and short VOT for [p], and high Fo. Some deviant behaviors improved post-cochlear implant. However, deviant behaviors often persisted for several years post-cochlear implant. There was considerable evidence of further development of deviant behaviors post-cochlear implant. All of the deaf children demonstrated deviancy on at least two of our measures at the last data collection interval (5 to 6 yr post-cochlear implant). Conclusions Children who received cochlear implants after 5 yr of age and who were educated in a Total Communication setting showed persistence and further development of deviant speech/voice behaviors for several years post-cochlear implant. Although our findings cannot be generalized to other populations of children with cochlear implants (i.e., those who were implanted earlier, those educated in auditory-oral programs), it seems wisest at the present time not to assume that children’s deviant speech/voice behaviors will remit spontaneously with continued cochlear implant use. Our data provide an important comparative database for future investigations of pediatric cochlear implant users who have had shorter periods of auditory deprivation and who have received cochlear implants with more current technological features. Longitudinal Changes in Children’s Speech and Voice Physiology after Cochlear Implantation

The effects of psychotherapy on behavior problems of sexually abused deaf children.

This study assessed the effectiveness of a broad based psychotherapeutic intervention with a sample of 72 children sexually abused at a residential school for the deaf. An untreated comparison group emerged when about half of their parents refused the offer for psychotherapy provided by the school. Treated and untreated children were randomly assigned to two assessment groups: those who participated in a pretreatment assessment and those who did not. Houseparents at the residential school used the Child Behavior Checklist (CBC) to rate the pretreatment assessment children before treatment and all 72 children one year after the implementation of psychotherapy. Children receiving therapy had significantly fewer behavior problems than children not receiving therapy. There was a differential response to therapy on the basis of sex. Boys receiving therapy had significantly lower scores on the following CBC scales than the no treatment group: Total, Internal, External, Somatic, Uncommunicative, Immature, Hostile, Delinquent, Aggressive, and Hyperactive. There were no differences on the Schizoid and Obsessive scales. Girls receiving therapy had significantly lower scores than the no treatment group on the following CBC scales: Total, External, Depressed, Aggressive, and Cruel. There were no differences on the Internal, Anxious, Schizoid, Immature, Somatic, and Delinquent scales.

EFFECT OF RELATIVE AND OVERALL AMPLITUDE ON PERCEPTION OF VOICELESS STOP CONSONANTS BY LISTENERS WITH NORMAL AND IMPAIRED HEARING

Previous studies of the /p/-/t/ contrast for normal-hearing listeners have shown that both manipulation of the amplitude of the burst relative to the vowel in the F4-F5 frequency region and overall presentation level can influence the perception of place of articulation [R. N. Ohde and K. N. Stevens, J. Acoust. Soc. Am. 74, 706-714 (1983); Gravel and Ohde, Asha 25, 101 (1983)], such that greater burst amplitude in the high frequencies and higher presentation levels result in more alveolar responses. The influence of relative amplitude and presentation level was tested for both normal-hearing (NH) and hearing-impaired (HI) listeners in the present study. Synthetic CV stimuli were used, and the amplitude of the burst relative to vowel-onset amplitude in the F4-F5 frequency region was manipulated across a 20-dB range. In addition, overall presentation level was varied across a 45-dB range. The findings revealed that the hearing-impaired listeners selected more alveolar responses than listeners with normal hearing when tested at equivalent SPLs. A group of five normal-hearing listeners were then presented the synthetic stimuli in a background of broadband noise at a level that produced thresholds at 4 kHz equivalent to the thresholds of five hearing-impaired listeners. Results from the noise-masked normal-hearing listeners did not consistently show more alveolar responses as presentation level of the stimuli was increased, thus failing to mimic the responses from the hearing-impaired listeners in quiet.

Articulatory changes with short-term deactivation of the cochlear implants of two prelingually deafened children.

Objective The purpose of this investigation was to determine how suddenly diminished auditory feedback affects articulatory behaviors for prelingually deafened children with cochlear implants (CIs). Design Two 6-yr-old children served as participants. Considering their level of hearing impairment, one child had above average speech perception and production skills while the other child had e-ceptionally good speech perception and production abilities. Baseline data were collected four times over the course of 2 days with the children wearing their CIs. For three additional days, data were collected while the children wore their CIs (ON condition) and then again after their CIs had been deactivated for 1 hr (OFF condition). Variables assessed included amount of jaw opening, F1, F2, nasal air flow, voice onset time (VOT), voicing duration, and the magnitude and duration of intraoral air pressure (Po). Findings were related to each other and to previously reported phonatory findings from the same two children (Higgins, McCleary, & Schulte, 1999) to determine whether changes in articulatory variables in the OFF condition were consistent with a direct effect of diminished auditory feedback or an indirect influence of suprasegmental parameters. Results Both children e-hibited consistent and significant changes in articulatory parameters in the absence of auditory feedback. Such changes occurred more often for the child who had especially proficient speech perception and production skills. Some changes (i.e., reduced Po for [p] and reduced nasal air flow for [m]) appeared related to the influence of suprasegmental parameters, in particular, reduced subglottal air pressure. Other effects (i.e., increased F2 for [|g] and reduced VOT for [p]) were suggestive of changes in the children’s abilities to maintain appropriate articulatory placements and timing. Finally, a few changes (reduced jaw opening for [i] and increased Po duration for [p]) may have reflected compensatory strategies to maintain correct tongue placement and enhance temporal distinctions in the absence of auditory feedback. Conclusions Based on the data of our two participants, it appears that some prelingually deafened children with CIs and good speech perception/production skills rely on auditory feedback to maintain articulatory precision. In the absence of auditory feedback, such children may demonstrate changes in articulatory placement and timing. In addition, data from one of our participants are consistent with the idea that some children may be aware that their articulatory control is compromised in the absence of auditory feedback and attempt to compensate by altering articulatory durations or the range of associated articulatory movements.

Correlates of vestibular evaluation results during the first year of life

Prenatal and perinatal correlates of abnormal auditory brainstem responses in neonates have been studied extensively. In contrast, vestibular function during the first year of life has received sparse attention. Using a specially modified vestibular test battery, 65 infants (17 low‐risk, 48 high‐risk) were initially evaluated during their first 6 months of life. Results revealed normal vestibular function in 46 infants (13 low‐risk, 33 high‐risk) and abnormal findings at either 3 or 6 months in 19 infants (4 low‐risk, 15 high‐risk). Correlations between vestibular results and variables such as auditory brainstem response results, birth history, and postnatal course in the neonatal intensive care unit were analyzed statistically. While some differences were mildly significant, none were highly significant. The lack of significant correlation between abnormal auditory brainstem response and vestibular results is of particular interest.

Altered phonatory physiology with short-term deactivation of children's cochlear implants.

OBJECTIVES The purposes of this investigation were 1) to determine whether short-term auditory deprivation results in systematic phonatory changes for prelingually deafened children who use cochlear implants (CIs) and 2) to determine whether such changes are similar to those that have been reported for postlingually deafened adults. DESIGN Participants were two 6-yr-old children with CIs. Both children had been prelingually deafened, had good to excellent speech production and speech perception skills, and had been using their CIs for 2.5 yr. A single-subject design was used. Intraoral air pressure (Po), phonatory air flow (Vl), electroglottograph (EGG) cycle width, fundamental frequency (F0), and intensity were measured during syllable production over two baseline days and three experimental days. Data were collected twice on each baseline day while the children wore their CIs, with a 1 hr break between data collection sessions. On experimental days, data were collected while the children wore their CIs (ON condition) and after their CIs had been removed for 1 hr (OFF condition). RESULTS Both children demonstrated highly variable phonatory behaviors in baseline. The child with the more proficient speech production and perception skills showed consistent and significant reductions in Po, F0, and intensity in the OFF condition. These findings were dissimilar to those that occurred with repeated testing in the baseline condition and so were attributed to the sudden loss of auditory feedback. The other child showed a consistent and significant increase in mean Vl in the OFF condition. However, this child exhibited a similar finding with repeated testing in the baseline condition. Therefore, increased Vl in the OFF condition may have represented a practice effect. She also showed a small and consistent decrease in F0 in the OFF condition when F0 was derived from acoustic data, but this effect was not reliable in another data set when F0 was derived from the EGG signal. Our results with prelingually deafened children were inconsistent with reports of increased intensity and F0 in the absence of auditory feedback for postlingually deafened adults with CIs. CONCLUSIONS Some prelingually deafened children who are successful CI users appear to use auditory feedback to self-monitor phonation. We suggest that the participant in our investigation who showed systematic phonatory changes in response to diminished auditory feedback was using auditory feedback primarily to stabilize her phonatory behaviors. She may not have had adequate experience with auditory feedback or adequate flexibility in her use of feedback mechanisms to implement the phonatory compensations that late-deafened adults use when auditory feedback suddenly is diminished. We further suggest that the phonatory changes that she exhibited during short-term auditory deprivation reflected disruption of her typical speaking strategies or apprehension about speaking when her ability to self-monitor auditorily was compromised.