The use of functional magnetic resonance imaging (fMRI) to explore central auditory function may be compromised by the intense bursts of stray acoustic noise produced by the scanner whenever the magnetic resonance signal is read out. We present results evaluating the use of one method to reduce the effect of the scanner noise: "sparse" temporal sampling. Using this technique, single volumes of brain images are acquired at the end of stimulus and baseline conditions. To optimize detection of the activation, images are taken near to the maxima and minima of the hemodynamic response during the experimental cycle. Thus, the effective auditory stimulus for the activation is not masked by the scanner noise. In experiment 1, the course of the hemodynamic response to auditory stimulation was mapped during continuous task performance. The mean peak of the response was at 10.5 sec after stimulus onset, with little further change until stimulus offset. In experiment 2, sparse imaging was used to acquire activation images. Despite the fewer samples with sparse imaging, this method successfully delimited broadly the same regions of activation as conventional continuous imaging. However, the mean percentage MR signal change within the region of interest was greater using sparse imaging. Auditory experiments that use continuous imaging methods may measure activation that is a result of an interaction between the stimulus and task factors (e.g., attentive effort) induced by the intense background noise. We suggest that sparse imaging is advantageous in auditory experiments as it ensures that the obtained activation depends on the stimulus alone.

Objective To estimate the prevalence of confirmed permanent childhood hearing impairment and its profile across age and degree of impairment in the United Kingdom. Design Retrospective total ascertainment through sources in the health and education sectors by postal questionnaire. Setting Hospital based otology and audiology departments, community health clinics, education services for hearing impaired children.

More quality of life is likely to be gained per unit of expenditure on unilateral implantation than bilateral implantation.

Compared with unilateral cochlear implantation, bilateral implantation is associated with better listening skills in severely-profoundly deaf children.

Objectives: The objectives of this study were to identify variables which are associated with differences in outcome among hearing-impaired children, and to control those variables while assessing the impact of cochlear implantation. Study design:In a cross-sectional study, the parents and teachers of a representative sample of hearing-impaired children were invited to complete questionnaires about children's auditory performance, spoken communication skills, educational achievements, and quality of life. Multiple regression was used to measure the strength of association between these outcomes and variables related to the child (average hearing level, age at onset of hearing impairment, age, gender, number of additional disabilities), the family (parental occupational skill level, ethnicity, and parental hearing status), and cochlear implantation.Results: Questionnaires were returned by the parents of 2858 children, 468 of whom had received a cochlear implant, and by the teachers of 2241 children, 383 of whom had received an implant. Across all domains, reported outcomes were better for children with fewer disabilities in addition to impaired hearing. Across most domains, reported outcomes were better for children who were older, female, with a more favourable average hearing level, with a higher parental occupational skill level, and with an onset of hearing-impairment after 3 years. When these variables were controlled, cochlear implantation was consistently associated with advantages in auditory performance and spoken communication skills, but less consistently associated with advantages in educational achievements and quality of life.Significant associations were found most commonly for children who were younger than 5 years when implanted, and had used implants for more than 4 years. TheseHearing-impaired children in the UK, I. 2 children, whose mean (pre-operative, un-aided) average hearing level was 118 dB, performed at the same level as non-implanted children with average hearing levels in the range from 80 dB to 104 dB, depending on the outcome measure. Conclusion:When rigorous statistical control is exercised in comparing implanted and non-implanted children, paediatric cochlear implantation is associated with reported improvements both in spoken communication skills and in some aspects of educational achievements and quality of life, provided that children receive implants before 5 years of age.(342 words)