The neural representation of an auditory spatial cue in the primate cortex.

Humans make use of small differences in the timing of sounds at the two ears-interaural time differences (ITDs)-to locate their sources. Despite extensive investigation, however, the neural representation of ITDs in the human brain is contentious, particularly the range of ITDs explicitly represented by dedicated neural detectors. Here, using magneto- and electro-encephalography (MEG and EEG), we demonstrate evidence of a sparse neural representation of ITDs in the human cortex.

Speech Comprehension by Cochlear Implant Users Assessed with Evoked Potentials and Response Times.

Introduction: Cochlear implant (CI) users differ greatly in their rehabilitation outcomes, including speech understanding in noise. This variability may be related to brain changes associated with intact senses recruiting cortical areas from stimulation-deprived senses. Numerous studies have demonstrated such cross-modal reorganization in individuals with untreated hearing loss.

The P300 Auditory Evoked Potential: A Physiological Measure of the Engagement of Cognitive Systems Contributing to Listening Effort?

Objectives: This study aimed to explore the potential of the P300 (P3b) as a physiological measure of the engagement of cognitive systems contributing to listening effort.

Design: Nineteen right-handed young adults (mean age: 24.79 years) and 20 right-handed older adults (mean age: 58.

Cortical haemodynamic responses predict individual ability to recognise vocal emotions with uninformative pitch cues but do not distinguish different emotions.

We investigated the cortical representation of emotional prosody in normal-hearing listeners using functional near-infrared spectroscopy (fNIRS) and behavioural assessments. Consistent with previous reports, listeners relied most heavily on F0 cues when recognizing emotion cues; performance was relatively poor-and highly variable between listeners-when only intensity and speech-rate cues were available. Using fNIRS to image cortical activity to speech utterances containing natural and reduced prosodic cues, we found right superior temporal gyrus (STG) to be most sensitive to emotional prosody, but no emotion-specific cortical activations, suggesting that while fNIRS might be suited to investigating cortical mechanisms supporting speech processing it is less suited to investigating cortical haemodynamic responses to individual vocal emotions.

Characterizing Cochlear implant artefact removal from EEG recordings using a real human model.

Electroencephography (EEG) recordings from CI listeners are contaminated by electrical artefacts that make it difficult to extract neural responses. Previously, we have removed these artefacts by means of interpolation and spatial filtering. However, the extent to which this method can effectively reduce electrical artefacts has not been fully investigated.

Analysis methods for measuring passive auditory fNIRS responses generated by a block-design paradigm.

Functional near-infrared spectroscopy (fNIRS) is an increasingly popular tool in auditory research, but the range of analysis procedures employed across studies may complicate the interpretation of data. We aim to assess the impact of different analysis procedures on the morphology, detection, and lateralization of auditory responses in fNIRS. Specifically, we determine whether averaging or generalized linear model (GLM)-based analysis generates different experimental conclusions when applied to a block-protocol design.

Neural encoding of spectro-temporal cues at slow and near speech-rate in cochlear implant users.

The ability to process rapid modulations in the spectro-temporal structure of sounds is critical for speech comprehension. For users of cochlear implants (CIs), spectral cues in speech are conveyed by differential stimulation of electrode contacts along the cochlea, and temporal cues in terms of the amplitude of stimulating electrical pulses, which track the amplitude-modulated (AM'ed) envelope of speech sounds. Whilst survival of inner-ear neurons and spread of electrical current are known factors that limit the representation of speech information in CI listeners, limitations in the neural representation of dynamic spectro-temporal cues common to speech are also likely to play a role.

The P300 auditory event-related potential as a method to assess the benefit of contralateral hearing aid use in bimodal listeners: a proof-of-concept.

Bimodal listeners vary in the amount of benefit they receive from wearing the contralateral hearing aid. This may partially depend on the listener's auditory processing capacities. The current study explores whether the P300 event-related potential can provide insight into the mechanisms underlying the benefits of wearing a contralateral hearing aid.

Age-Related Changes in Binaural Interaction at Brainstem Level.

Objectives: Age-related hearing loss hampers the ability to understand speech in adverse listening conditions. This is attributed to a complex interaction of changes in the peripheral and central auditory system. One aspect that may deteriorate across the lifespan is binaural interaction.

Binaural interaction in the auditory brainstem response: a normative study.

Objective: Binaural interaction can be investigated using auditory evoked potentials. A binaural interaction component can be derived from the auditory brainstem response (ABR-BIC) and is considered evidence for binaural interaction at the level of the brainstem. Although click ABR-BIC has been investigated thoroughly, data on 500 Hz tone-burst (TB) ABR-BICs are scarce.