Biomedical subjects

Rachael Frush Holt

Publications and source records attributed to Rachael Frush Holt.

3 recordsLinked to original sources

PubMed2005

Multiple looks in speech sound discrimination in adults.

N. F. Viemeister and G. H. Wakefield's (1991) multiple looks hypothesis is a theoretical approach from the psychoacoustic literature that has promise for bridging the gap between results from speech perception research and results from psychoacoustic research. This hypothesis accounts for sensory detection data and predicts that if the "looks" at a stimulus are independent and information is combined optimally, sensitivity should increase for 2 pulses relative to 1 pulse. Specifically, d' (a bias-free measure of sensitivity) for 2 pulses should be larger than d' for 1 pulse. One speech discrimination paradigm that presents stimuli with multiple presentations is the change/no-change procedure. On a change trial, the standard and comparison stimuli differ; on a no-change trial, they are the same. Normal-hearing adults were tested using the change/no-change procedure with 3 consonant-vowel minimal pairs in combinations of 1, 2, and 4 repetitions of standard and comparison stimuli at various signal-to-noise ratios. If multiple looks extend to this procedure, performance should increase with higher repetition numbers. Performance increased with more presentations of the speech contrasts tested. The multiple looks hypothesis predicted performance better at low repetition numbers when performance was near d' values of 1.0 than at higher repetition numbers and higher performance levels.

Adult↗

PubMed2005

Speech and language development in cognitively delayed children with cochlear implants.

OBJECTIVE: The primary goals of this investigation were to examine the speech and language development of deaf children with cochlear implants and mild cognitive delay and to compare their gains with those of children with cochlear implants who do not have this additional impairment. DESIGN: We retrospectively examined the speech and language development of 69 children with pre-lingual deafness. The experimental group consisted of 19 children with cognitive delays and no other disabilities (mean age at implantation = 38 months). The control group consisted of 50 children who did not have cognitive delays or any other identified disability. The control group was stratified by primary communication mode: half used total communication (mean age at implantation = 32 months) and the other half used oral communication (mean age at implantation = 26 months). Children were tested on a variety of standard speech and language measures and one test of auditory skill development at 6-month intervals. RESULTS: The results from each test were collapsed from blocks of two consecutive 6-month intervals to calculate group mean scores before implantation and at 1-year intervals after implantation. The children with cognitive delays and those without such delays demonstrated significant improvement in their speech and language skills over time on every test administered. Children with cognitive delays had significantly lower scores than typically developing children on two of the three measures of receptive and expressive language and had significantly slower rates of auditory-only sentence recognition development. Finally, there were no significant group differences in auditory skill development based on parental reports or in auditory-only or multimodal word recognition. CONCLUSIONS: The results suggest that deaf children with mild cognitive impairments benefit from cochlear implantation. Specifically, improvements are evident in their ability to perceive speech and in their reception and use of language. However, it may be reduced relative to their typically developing peers with cochlear implants, particularly in domains that require higher level skills, such as sentence recognition and receptive and expressive language. These findings suggest that children with mild cognitive deficits be considered for cochlear implantation with less trepidation than has been the case in the past. Although their speech and language gains may be tempered by their cognitive abilities, these limitations do not appear to preclude benefit from cochlear implant stimulation, as assessed by traditional measures of speech and language development.

Child, Preschool↗

PubMed2005

Spoken word recognition development in children with residual hearing using cochlear implants and hearing AIDS in opposite ears.

OBJECTIVE: With broadening candidacy criteria for cochlear implantation, a greater number of pediatric candidates have usable residual hearing in their nonimplanted ears. This population potentially stands to benefit from continued use of conventional amplification in their nonimplanted ears. The purposes of this investigation were to evaluate whether children with residual hearing in their nonimplanted ears benefit from bilateral use of cochlear implants and hearing aids and to investigate the time course of adaptation to combined use of the devices together. DESIGN: Pediatric cochlear implant recipients with severe sensorineural hearing loss in their nonimplanted ears served as participants. Ten children continued to use hearing aids in their nonimplanted ears after cochlear implantation; 12 children used their cochlear implants exclusively. Participants were tested longitudinally on spoken word recognition measures at 6-month intervals. The children who continued wearing hearing aids were tested in three sensory aid conditions: cochlear implants alone, hearing aids alone, and cochlear implants in conjunction with hearing aids. The children who did not continue hearing aid use were tested after surgery in their only aided condition, cochlear implant alone. RESULTS: The results suggest that children with severe hearing loss who continued using hearing aids in their nonimplanted ears benefited from combining the acoustic input received from a hearing aid with the input received from a cochlear implant, particularly in background noise. However, this benefit emerged with experience. CONCLUSIONS: Our findings suggest that it is appropriate to encourage pediatric cochlear implant recipients with severe hearing loss to continue wearing an appropriately fitted hearing aid in the nonimplanted ear to maximally benefit from bilateral stimulation.

Adaptation, Physiological↗