Cortical response to auditory motion suggests an asymmetry in the reliance on inter-hemispheric connections between the left and right auditory cortices.

The aim of the current study was to measure the brain's response to auditory motion using electroencephalography (EEG) to gain insight into the mechanisms by which hemispheric lateralization for auditory spatial processing is established in the human brain. The onset of left- or rightward motion in an otherwise continuous sound was found to elicit a large response, which appeared to arise from higher-level nonprimary auditory areas. This motion onset response was strongly lateralized to the hemisphere contralateral to the direction of motion.

Vowel processing evokes a large sustained response anterior to primary auditory cortex.

The present study uses electroencephalography (EEG) and a new stimulation paradigm, the 'continuous stimulation paradigm', to investigate the neural correlate of phonological processing in human auditory cortex. Evoked responses were recorded to stimuli consisting of a control sound (1000 ms) immediately followed by a test sound (150 ms). On half of the trials, the control sound was a noise and the test sound a vowel; to control for unavoidable effects of spectral change at the transition, the roles of the stimuli were reversed on the other half of the trials.

Single-trial EEG-fMRI reveals the dynamics of cognitive function.

Two major non-invasive techniques in cognitive neuroscience, electroencephalography (EEG) and functional magnetic resonance imaging (fMRI), have complementary advantages with regard to their spatial and temporal resolution. Recent hardware and software developments have made it feasible to acquire EEG and fMRI data simultaneously. We emphasize the potential of simultaneous EEG and fMRI recordings to pursue new strategies in cognitive neuroimaging.

Contributions of intrinsic neural and stimulus variance to binaural sensitivity.

The discrimination of a change in a stimulus is determined both by the magnitude of that change and by the variability in the neural response to the stimulus. When the stimulus is itself noisy, then the relative contributions of the neural (intrinsic) and stimulus induced variability becomes a critical question. We measured the contribution of intrinsic neural noise and interstimulus variability to the discrimination of interaural time differences (ITDs) and interaural correlation (IAC).

Discrimination learning induced by training with identical stimuli.

Sensory stimuli become easier to detect or distinguish with practice. It is generally assumed that the task-relevant stimulus dimension becomes increasingly more salient as a result of attentively performing the task at a level that is neither too easy nor too difficult. However, here we show improved auditory frequency discrimination following training with physically identical tones that were impossible to discriminate.

Hearing-impaired children in the United Kingdom, IV: cost-effectiveness of pediatric cochlear implantation.

Objective: To estimate the cost-effectiveness of pediatric cochlear implantation by conducting a cost-utility analysis from a societal perspective.

Design: In a cross-sectional survey, the parents of a representative sample of hearing-impaired children assessed the health utility of their child using a revised version of the Health Utilities Index Mark III questionnaire. Linear regression was used to estimate the gain in health utility associated with implantation while controlling for eight potentially confounding variables: average (4-frequency, unaided, preoperative) hearing level (AHL), age at onset of hearing-impairment, age, gender, number of additional disabilities, parental occupational skill level, ethnicity, and parental hearing status.

Hearing-impaired children in the United Kingdom, III: cochlear implantation and the economic costs incurred by families.

Objectives: This article addresses two questions. First, are there differences in the economic costs incurred by families of hearing-impaired children depending on whether or not children have cochlear implants? Second, are these differences important when assessed from the perspective of society?

Methods: In a cross-sectional survey, parents of a representative sample of hearing-impaired children provided data about annual resources used by the family because of their child's hearing impairment. The data yielded estimates of two variables: out-of-pocket expenditure and time away from normal activities by parents.

Two-eared listening in dynamic situations.

Reports of hearing disabilities, particularly those acoustically and perceptually dynamic circumstances, are associated with compromised binaural capacities. Those disabilities that are compromised largely correspond to the areas where benefits of bilateral fitting over unilateral fitting emerge. The singular exception is for disabilities in "Sound quality and naturalness".

Self-reported benefits from successive bilateral cochlear implantation in post-lingually deafened adults: randomised controlled trial.

Adult users of unilateral Nucleus CI24 cochlear implants with the SPEAK processing strategy were randomised either to receive a second identical implant in the contralateral ear immediately, or to wait 12 months while they acted as controls for late-emerging benefits of the first implant. Twenty four subjects, twelve from each group, completed the study. Receipt of a second implant led to improvements in self-reported abilities in spatial hearing, quality of hearing, and hearing for speech, but to generally non-significant changes in measures of quality of life.

The psychoacoustics of binaural hearing.

This paper introduces the major phenomena of binaural hearing. The sounds arriving at the two ears are rarely the same: usually one ear will be partially shadowed from the sound source by the head, and the sound will also have to travel further to get to that ear. The resulting differences in interaural level and time can be detected by the auditory system and can be used to determine the direction of the source of sound.

An exploration of demographic bias in a questionnaire survey of hearing-impaired children: implications for comparisons of children with and without cochlear implants.

Objectives: Responders to questionnaire surveys, who are self-selecting, are generally accepted to be unrepresentative of the total available population, at least in demographic terms. Since demographic and other variables are known to be predictive of outcome, it is important to understand the extent of that unrepresentativeness when using survey data to report comparisons of outcome. This paper aims (i) to evaluate the extent to which a sample of hearing-impaired children surveyed by postal questionnaire was representative of the population of hearing-impaired children in the United Kingdom (UK), and (ii) to identify demographic differences between children with and without cochlear implants.

Volterra Slice otoacoustic emissions recorded using maximum length sequences from patients with sensorineural hearing loss.

When normally hearing ears are stimulated with maximum length sequences (MLS) of clicks, a family of non-linear temporal interaction components of otoacoustic emissions (OAEs) can be derived, which have been named Volterra Slice OAEs (VS OAEs). This study investigates the sensitivity of VS OAEs to sensorineural hearing impairment in adults, compared to that of the widely used derived non-linear click evoked OAE (DNL CEOAE). VS OAEs and DNL CEOAEs were obtained from 24 normally hearing and 24 hearing impaired ears using a custom-built MLS system and a Otodynamics 'ILO88' OAE Analyzer, respectively.

Nonlinear properties of otoacoustic emissions in normal and impaired hearing.

Click-evoked otoacoustic emissions (CEOAEs) exhibit nonlinearities in amplitude and time domains. The first objective of this study was to investigate whether there is any correlation between the temporal and amplitude nonlinearities of CEOAEs in normals. Additionally there is evidence that pathology affects the normal cochlear nonlinearity.

An investigation into the relationship between input-output nonlinearities and rate-induced nonlinearities of click-evoked otoacoustic emissions recorded using maximum length sequences.

The maximum length sequence (MLS) technique allows otoacoustic emissions (OAEs) to be recorded using clicks presented at very high presentation rates. It has previously been found that increasing the click presentation rate leads to increasing suppression (termed "rate-suppression") of the MLS evoked OAE (Hine, J.E.

Evidence for a direct, short latency projection from the dorsal cochlear nucleus to the auditory thalamus in the guinea pig.

The auditory thalamus (medial geniculate body, MGB) receives its main ascending input from the inferior colliculus (IC), which was considered to be an obligatory relay for all auditory inputs to the MGB. However, recent anatomical evidence in the rat [ (Malmierca et al. 2002) J.

Response preferences for "what" and "where" in human non-primary auditory cortex.

Primate studies suggest the auditory cortex is organized in at least two anatomically and functionally separate pathways: a ventral pathway specializing in object recognition and a dorsal pathway specializing in object localization. The current experiment assesses the validity of this model in human listeners using fMRI to investigate the neural substrates of spatial and non-spatial temporal pattern information. Targets were differentiated from non-targets on the basis of two levels of pitch information (present vs.

A comparison of adaptive procedures for rapid and reliable threshold assessment and training in naive listeners.

In psychoacoustic studies there is often a need to assess performance indices quickly and reliably. The aim of this study was to establish a quick and reliable procedure for evaluating thresholds in backward masking and frequency discrimination tasks. Based on simulations, four procedures likely to produce the best results were selected, and data collected from 20 naive adult listeners on each.

Linear and nonlinear hearing aid fittings--2. Patterns of candidature.

We studied candidature for linear, slow-acting AVC hearing aids, and fast-acting WDRC hearing aids in a within-subject within-device crossover design of 50 listeners with SNHL. Candidature dimensions include HTLs, ULLs, spectro-temporal and masking abnormalities, cognitive capacity, and self-reports and acoustic measures of auditory ecology. Better performance with linear fittings is associated with flatter audiograms, wider dynamic range, and smaller differences in dynamic range between low and high frequencies, and also with more restricted auditory lifestyles.

Linear and nonlinear hearing aid fittings--1. Patterns of benefit.

We evaluated the benefits of fast-acting WDRC, slow-acting AVC, and linear reference fittings for speech intelligibility and reported disability, in a within-subject within-device masked crossover design on 50 listeners with SNHL. Five hearing aid fittings were implemented having two compression channels and seven frequency bands. Each listener sequentially experienced each fitting for a 10-week period.

Auditory processing disorder (APD)-potential contribution of mouse research.

APD is a common, heterogeneous and poorly understood listening impairment that is receiving increasing recognition, especially in children and the elderly. The primary symptom in humans is poor speech perception despite normal pure tone audiometry. Diagnostic practice is patchy, but current proposals are to distinguish APD by reduced ability to detect, discriminate, localize and order non-speech sounds.

Hearing-impaired children in the United Kingdom, II: Cochlear implantation and the cost of compulsory education.

Objective: The objective of this study was to estimate the impact of cochlear implantation on the cost of compulsory education of hearing-impaired children in the United Kingdom.

Study Design: In a cross-sectional survey, teachers were asked to report the school placement of, and amount of support provided to, a representative sample of hearing-impaired children. Costs of school placement were obtained from published sources.

Hearing-impaired children in the United Kingdom, I: Auditory performance, communication skills, educational achievements, quality of life, and cochlear implantation.

Objectives: The objectives of this study were to identify variables that 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.

Does patient-perceived handicap correspond to the modified clinical test for the sensory interaction on balance?

Objective: To determine whether patient self-reported handicap correlates with scores obtained from the modified Clinical Test for the Sensory Interaction on Balance as assessed by the Neurocom VSR Balance Master platform.

Study Design: Prospective observational.

Setting: Balance clinic in tertiary referral center.