537 results match your criteria: "MRC Institute of Hearing[Affiliation]"
J Acoust Soc Am
December 2001
MRC Institute of Hearing Research, University Park, Nottingham, United Kingdom.
Functional magnetic resonance imaging (fMRI) provides a noninvasive tool for observing correlates of neural activity in the brain while a subject listens to sound. However, intense acoustic noise is generated in the process of capturing MR images. This noise stimulates the auditory nervous system, limiting the dynamic range available for displaying stimulus-driven activity.
View Article and Find Full Text PDFCereb Cortex
February 2002
MRC Institute of Hearing Research, University Park, Nottingham NG7 2RD, UK.
Neuroimage
December 2001
MRC Institute of Hearing Research, University Park, Nottingham NG7 2RD, United Kingdom.
Structural equation modeling (SEM) of neuroimaging data can be evaluated both for the goodness of fit of the model and for the strength of path coefficients (as an index of effective connectivity). SEM of auditory fMRI data is made difficult by the necessary sparse temporal sampling of the time series (to avoid contamination of auditory activation by the response to scanner noise) and by the paucity of well-defined anatomical information to constrain the functional model. We used SEM (i.
View Article and Find Full Text PDFBr J Audiol
June 2001
MRC Institute of Hearing Research, University Park, Nottingham, UK.
Three groups of children undertook an interactive computer-based closed-set test of the ability to identify pre-recorded spoken words presented acoustically. The test was completed by 31/39 children with profound hearing loss who had used the Nucleus Spectra-22 cochlear-implant system for at least one year (Group A); by 30 children with normal hearing (Group B); and by 22 children with severe-profound hearing loss who used acoustic hearing aids (Group C). Among the implanted children, those who were younger when implanted and who had used their devices for longer produced higher scores (multiple-r = 0.
View Article and Find Full Text PDFBMJ
September 2001
MRC Institute of Hearing Research, University Park, Nottingham NG7 2RD.
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.
Trends Amplif
September 2001
MRC Institute of Hearing Research (Scottish Section), Glasgow Royal Infirmary, North Glasgow University Hospitals NHS Trust, Glasgow, Scotland.
Am J Audiol
June 2001
MRC Institute of Hearing Research, Nottingham University, United Kingdom.
After a brief review of the history of newborn hearing screening including the Downs behavioral testing procedure, the Crib-o-gram and similar devices, and the use of auropalpebral reflex and otoacoustic emissions, there is a discussion of key issues that need to be resolved before universal hearing screening is introduced. Included are questions regarding the target population(s) of screening programs, well baby versus NICU screening, dealing with false-positives and the effects on parent-child relationships, and finally, the availability of resources for screening and follow-up. The results of a recent study in the United Kingdom that assessed the current state of audiology services and found there is a difference between existing standards and what is actually being done in practice, are presented and considered in terms of current trends in the United States to move ahead with universal screening without a solid database of information regarding the preparedness of clinical centers to deal with the need for services that will result from the initiation of universal programs.
View Article and Find Full Text PDFJ Health Serv Res Policy
July 2001
MRC Institute of Hearing Research, University of Nottingham, UK.
Objectives: To evaluate the effect of a risk factor checklist and training video for general practitioners in reducing inter-practice variation and improving the appropriateness of referrals (assessed by their positive predictive value or PPV) of patients with suspected otitis media with effusion (OME or 'glue ear') to secondary care.
Methods: Fifty general practices (177 practitioners) from the NHS Trent region and the West of Scotland were cluster-randomised either to a control group (n = 12) or to one of three intervention groups (training video (n = 16), checklist (n = 11), or both (n = 11)). Data on all paediatric ear, nose and throat (ENT) referrals and diagnostic results at ENT clinics were collected for a one-year period pre- and post-intervention.
Arch Dis Child
August 2001
MRC Institute of Hearing Research, University Park, Nottingham, UK.
Objective: To examine whether behavioural or cognitive sequelae of otitis media with effusion (OME) continue into late childhood and the early teens (11-18 years).
Setting: Data from a large multipurpose birth cohort study: the Dunedin multidisciplinary health and development study.
Participants: Around 1000 children from the study.
Int J Pediatr Otorhinolaryngol
July 2001
MRC Institute of Hearing Research, Nottingham, UK.
Objective: The impact of a randomised controlled trial (RCT) upon practice depends on its external validity (generalisability). This paper summarises and illustrates a framework for judging and augmenting external validity, emphasising its application to treatment trials in otitis media with effusion (OME) so as to permit stronger inferences in the future.
Methods: The external validity of two surgical trials in the field of OME (TARGET, UK and KNOOP-3, the Netherlands) has been examined within a framework emphasising effect modification, in four specific ways: (1) comparison of the demographic characteristics of the trial population with the domain population; (2) studying the distributions on possible effect modifiers (i.
Ear Hear
June 2001
MRC Institute of Hearing Research Clinical Section, University Hospital, Nottingham, England.
Objective: During measurement of transient evoked otoacoustic emissions (TEOAEs), acoustic stimulation of the contralateral ear reduces or suppresses TEOAE amplitude. This is thought to be due to the inhibitory control that the medial efferent auditory nerve exerts on outer hair cell (OHC) function. The main aim of this study was to investigate the effect of cerebello-pontine angle (CPA) tumor on the medial efferent nerve pathways to both tumor and non-tumor ears by examining alterations in TEOAE amplitude that result from contralateral acoustic stimulation.
View Article and Find Full Text PDFHear Res
June 2001
MRC Institute of Hearing Research, Royal South Hants Hospital, Southampton, UK.
Presenting clicks according to maximum length sequences (MLSs) enables transient evoked otoacoustic emissions (TEOAEs) to be recorded at very high stimulation rates. Despite a decrease in TEOAE amplitude, the very large number of responses obtainable at high rates means that both signal to noise ratio (SNR) and detection sensitivity increase as the click rate increases. This study characterises conventional and MLS TEOAEs near threshold for a group of normally hearing adults.
View Article and Find Full Text PDFClin Neurophysiol
May 2001
MRC Institute of Hearing Research, Royal South Hants Hospital, Brinton's Terrace, SO14 0YG, Southampton, UK.
Objectives: The objective of this study was to examine whether temporal non-linearities of the cochlear amplifier, as reflected by otoacoustic emissions (OAEs), exist and are distinct from any recording system non-linearities.
Methods: Maximum length sequence stimulation, at various stimulus rates, was used to evoke OAEs from normally hearing subjects. Recordings from a 2cc cavity were also made.
J Acoust Soc Am
April 2001
MRC Institute of Hearing Research, University Park, Nottingham, United Kingdom.
Effects of sound level on auditory cortical activation are seen in neuroimaging data. However, factors such as the cortical response to the intense ambient scanner noise and to the bandwidth of the acoustic stimuli will both confound precise quantification and interpretation of such sound-level effects. The present study used temporally "sparse" imaging to reduce effects of scanner noise.
View Article and Find Full Text PDFBr J Audiol
February 2001
MRC Institute of Hearing Research, University Park, Nottingham, UK.
The terms 'sensitivity' and 'specificity' are defined and some of the factors that determine their values are discussed in the context of screening for permanent childhood hearing loss. There is a need to distinguish between the values observed in 'simple experiments' and those that may be obtained under more realistic 'field' conditions. It is not feasible to give a meta-analytic overview of published data because of the variety of methods and objectives used in those studies published in the literature.
View Article and Find Full Text PDFTrends Mol Med
March 2001
MRC Institute of Hearing Research, University of Nottingham, Nottingham, UK NG7 2RD.
Nat Neurosci
April 2001
MRC Institute of Hearing Research, Science Road, University of Nottingham, Nottingham NG7 2RD, UK.
We report a systematic relationship between sound-frequency tuning and sensitivity to interaural time delays for neurons in the midbrain nucleus of the inferior colliculus; neurons with relatively low best frequencies (BFs) showed response peaks at long delays, whereas neurons with relatively high BFs showed response peaks at short delays. The consequence of this relationship is that the steepest region of the function relating discharge rate to interaural time delay (ITD) fell close to midline for all neurons irrespective of BF. These data provide support for a processing of the output of coincidence detectors subserving low-frequency sound localization in which the location of a sound source is determined by the activity in two broad, hemispheric spatial channels, rather than numerous channels tuned to discrete spatial positions.
View Article and Find Full Text PDFNeuroreport
December 2000
MRC Institute of Hearing Research, University Park, Nottingham, UK.
Phase-locked responses to pure tones are a characteristic of most auditory cells at the level of the brain stem and allow sophisticated analyses based on coincidence detection. Phase-locking to tones has not previously been shown at the level of the auditory cortex in single unit studies. We have now identified phase-locked responses in 10% of low-frequency (< 1 kHz) units in the ventrorostral belt, a strip of cortex immediately ventral to the primary auditory area.
View Article and Find Full Text PDFHear Res
November 2000
MRC Institute of Hearing Research, University of Nottingham, University Park, Nottingham, UK.
Convergent input from cells in the medial superior olive (MSO) and lateral superior olive (LSO) onto a single inferior colliculus (IC) cell explains many findings that are not compatible with a simple coincidence detector mechanism. Here this explanation is tested using a physiologically accurate computer model of the binaural pathway in which the input to the IC cell is either from two MSO cells or a MSO and a LSO cell. Auditory nerve (AN) spike trains are formed by a stochastic hair cell model following a basilar membrane simulation using a gammatone filter.
View Article and Find Full Text PDFBr J Audiol
August 2000
MRC Institute of Hearing Research, Notthingham, UK.
Surprisingly little evidence is available in children between the ages of 3 and 7 years on the effect on hearing thresholds of the method of audiometry and of the developmental ability to concentrate and to respond. The Trial of Alternative Regimens in Glue Ear Treatment (TARGET) is a large, national, multi-centre trial of surgical intervention in children with otitis media with effusion (OME) that offers an opportunity to study these effects. Of 1517 children, aged between 3.
View Article and Find Full Text PDFEar Hear
August 2000
MRC Institute of Hearing Research, North Glasgow University Hospitals, NHS Trust, Glasgow Royal Infirmary, Scotland.
No outcome measure has universal validity and applicability. When designing, promulgating or selecting a particular instrument, audiologists should take care to consider and specify the detailed purposes to which the measure will be directed, and the particular populations to which it will be applied. Scales that have been optimized in one arena will have limited (though perhaps still useful) generalizability.
View Article and Find Full Text PDFClin Otolaryngol Allied Sci
August 2000
The MRC Institute of Hearing Research, University Park, Nottingham, UK.
These guidelines aim to assist in the diagnosis of noise-induced hearing loss (NIHL) in medicolegal settings. The task is to distinguish between possibility and probability, the legal criterion being 'more probable than not'. It is argued that the amount of NIHL needed to qualify for that diagnosis is that which is reliably measurable and identifiable on the audiogram.
View Article and Find Full Text PDFAudiology
December 2000
MRC Institute of Hearing Research, University Park, Nottingham, United Kingdom.
The objective of the study was to investigate childhood hearing impairment in a population-based sample from a genetic perspective. Participants included 82 families with hearing-impaired children (aged 4-13) previously ascertained in the Trent Health Region. A questionnaire was mailed to all families, followed by a home visit and Connexin-26 35delG mutation screen.
View Article and Find Full Text PDFJ Magn Reson Imaging
July 2000
MRC Institute of Hearing Research, Nottingham, United Kingdom.
This paper describes systematic methods for measuring and controlling sound levels within a magnetic resonance scanner. The methods are illustrated by application to the acoustic noise generated by a 3 T scanner during echoplanar imaging (EPI). Across five measurement sessions, sound pressure levels at the center of the head gradient coil ranged from 122 to 131 dB SPL [123 to 132 dB(A)].
View Article and Find Full Text PDFResults Probl Cell Differ
December 2000
MRC Institute of Hearing Research, Nottingham, UK.