Biomedical subjects

Mark E Lutman

Publications and source records attributed to Mark E Lutman.

21 records · Page 2Linked to original sources

PubMed2002

The educational settings of profoundly deaf children with cochlear implants compared with age-matched peers with hearing aids: implications for management.

The educational settings of 42 implanted profoundly deaf children 3 years after implantation were compared with the respective settings of 635 age-matched severely deaf and 511 profoundly deaf children with hearing aids. All implanted children received their implants before beginning school. The results revealed that 3 years after implantation. 38% (16 children) of the implanted profoundly deaf children attended mainstream schools, whereas 57% (24 children) were in a unit, or special class, in a mainstream school, and 5% (two children) were in schools for the deaf. With regard to the age-matched profoundly deaf children with hearing aids, 12% (63 children) attended mainstream schools, whereas 55% (281 children) were in a unit of a mainstream school, and 33% (167 children) were in schools for the deaf. In the group of age-matched severely deaf children, 38% (239 children) attended mainstream schools, whereas 51% (326 children) were in a unit of a mainstream school, and 11% (70 children) were in schools for the deaf. Statistical analysis revealed a highly significant difference between the educational placement of implanted children and hearing-aided profoundly deaf children (p<0.00001), whereas there was no statistically significant difference between implanted children and hearing-aided severely deaf children. In conclusion, implanted profoundly deaf children who have received their implants before beginning school have the same profile of educational placement as aided severely deaf children rather than aided profoundly deaf children of the same age in the UK. This is likely to have significant implications for the future management of profoundly deaf children and to influence future planning of educational support services.

Child↗

PubMed2002

An investigation of the use of band-limited chirp stimuli to obtain the auditory brainstem response.

Auditory brainstem responses (ABRs) using clicks enable global objective estimation of hearing threshold. Recently, it has been suggested that a chirp stimulus may produce a synchronous response from a larger portion of the basilar membrane than a click, and that a chirp will produce a greater amplitude response than a click at the same sensation level. Various workers have modified the stimulus to achieve frequency specificity (e.g. using tone-bursts). The present investigation used band-limited chirp stimuli having the same frequency-delay characteristics as the chirp mentioned above that compensate for frequency-dependent cochlear delays. The intention was to generate highly synchronized neural responses across parts of the nerve fibre array. Stimuli were presented at sensation levels between 10 and 50 dB to 10 adult subjects. Wave V was consistently identifiable even for low-frequency stimuli. Wave V amplitude increased and latency decreased as stimulus frequency increased. The latency decrease is consistent with high-frequency responses arising from basal regions of the cochlea. ABR thresholds were defined by objective estimation and visual inspection. Average ABR thresholds were 16 dB higher than behavioural thresholds for high-frequency chirps (3000-6000 Hz), increasing to 25 dB for low-frequency chirps (375-750 Hz). These ABR thresholds are closer to behavioural thresholds and have a smaller variance than reported for tone-burst stimuli without masking. However, they are not as close as those reported for tone-bursts in notched noise. The disadvantage of the band-limited chirps is that they have a wider spectral spread than tone-bursts and hence may elicit a response from unwanted frequency regions of the basilar membrane.

Acoustic Stimulation↗

PubMedDate not supplied

Self-reported outcome in new hearing aid users over a 24-week post-fitting period.

Evidence for the existence of auditory acclimatization is mixed, and the implications for clinical practice are unclear. The aim of this study was to seek evidence of perceived changes in performance over a 24-week post-fitting period. Thirty-two new, elderly subjects were recruited and fitted monaurally with the same model of linear, programmable hearing aid that provided in excess of 20-dB insertion gain at 2000-4000 Hz. The Glasgow Hearing Aid Benefit Profile (GHABP) was used to measure self-reported changes over time. The questions concerning benefit and satisfaction were modified to produce two versions: half of the subjects reported changes relative to the time of fitting, while the remainder reported changes relative to the previous occasion on which they completed the GHABP (3 weeks earlier). Subjects reported using hearing aids in excess of 90% of the time when in listening situations that cause difficulty. The median residual disability measure from the GHABP remained low (10-20%) over the duration of the study. The median scores for additional benefit and satisfaction showed a small but statistically significant improvement over the first 3 months of hearing aid use but only for the subjects who referenced this to their perceived performance 3 weeks earlier. The limited evidence for self-reported improvements in benefit and satisfaction over time reported to date must be tempered by the possibility of response bias arising from the method used to measure changes over time.

Adaptation, Physiological↗