The listening brain

Advancing listening technologies

Our researchers explore the neural basis of listening to advance the design and implementation of listening technologies for hearing devices.

Learn more about the projects we are undertaking in this area, and the research teams involved in them.

Predicting and optimising outcomes in cochlear implant users

Funded by: Macquarie University Cochlear Research joint Fund

This project seeks to explore the feasibility of using Functional Near -Infrared Spectroscopy for pre-, intra- and post-operative functional brain mapping activity in cochlear implant candidates and recipients.

Our aim is to develop a simple, non-invasive assay, that can guide expectations and rehabilitation.

Forming and following auditory objects

Funded by: William Demant Foundation

Despite extensive investigations into acoustic features underpinning the perception of auditory objects, neural mechanisms underlying object formation remain poorly understood. This program aims to:

• determine how the auditory brain represents objects from acoustic backgrounds
• investigate how the perception and neural representation of auditory objects varies in listeners with hearing impairment
• consider how altering the precision of foreground cues influences the perception and neural representation of auditory objects
• examine how accurate representation of the statistical structure of background sounds facilitates the formation of auditory objects and improves listening abilities in challenging acoustic environments
• use fNIRS neuroimaging technology to investigate brain mechanisms responsible for the forming and following of auditory objects.

Listen and Learn – Statistical Learning and the Adapting Auditory Brain

Funded by: Australian Research Council

Learning is critical to survival and occurs over different time-scales – developmental, the life course, moment-by-moment – to facilitate a diverse range of abilities from the acquisition of language, honing of skills and social behaviours, to detection of rapid changes in complex scenes.

This project examines statistical learning and assesses its contribution to the ability to listen and learn in our noisy world.

The overall aim of this project is to explore statistical learning in human listeners, focusing on understanding the role of rapid neural adaptation in learning over the short term, and the maintenance of learning over the longer term.

Autism and the adapting auditory brain

Funded by: Simons Foundation – SFARI – Grant RFA-873809

The project examines the auditory experiences of autistic people, focusing on how real-world soundscapes affect their everyday lives. We are investigating experiences of speech and phonemes in different acoustic environments, and how autistic people adapt to and process auditory textures.

By understanding autistic people's attributes, auditory perceptions and experiences, this project aims to:

• determine relationships between autistic traits, auditory experience and diagnosable auditory conditions in autistic people
• identify barriers from the acoustic environment in everyday life to desired participation for autistic people in the community
• learn how we can better support autistic people with strategies and technologies to facilitate accessibility and desired opportunities in daily life.

Brain connectivity in hearing loss

Funded by: German Science Foundation (DFG), European Union, CI industry

Our research is focused on 'nature and nurture' in brain development – on consequences of altered sensory experience on development with particular focus on deafness.

We study methods of its compensation by neuroprostheses and the plastic adaptation of the brain to the neuroprosthetic stimulation.

So far, the cochlear implant has been the clinically most successful neuroprosthetic device. We work on its further improvements and search for alternative ways of the stimulation of neurons in general, including stimulation within the central auditory system and the brain.

Uncovering central gain mechanisms in the subcortex

Central gain is a delicate balance of inhibitory and excitatory neurons in the brain. When disturbed, it can lead to run-away gain, like the screech of loudspeakers in a public address system when a microphone is brought closer. Except, in the auditory brain it can lead to tinnitus – phantom ringing – and hyperacusis – reduced tolerance to loud sounds.

We are studying mechanisms in the human auditory brainstem using non-invasive techniques that has the potential to detect subtle changes in central gain early, ie before individuals develop hearing loss, tinnitus, and hyperacusis. Such early detection can help in earlier administration of therapeutics or changing lifestyle.

Developing a rapid, cheap, and informative hearing screening test

Funded by: Macquarie University Cochlear Research joint Fund, National Acoustic Laboratories, Royal National Institute for the Deaf (UK)

Newborn hearing screening (NBHS) is a critical program that, by detecting hearing loss at birth, provides the best opportunity for the child’s speech and language development through the provision of hearing aids or cochlear implants.

Australia is the world leader in NBHS. However, we use one of the costliest, and less informative, technologies in our NBHS.

We are working on a new-age tool that cleverly repurposes existing cheaper technology to provide us more information about hearing deficit. We envision our new test could cut costs owing to lesser running costs (consumables, training), and faster triage of newborns to the correct audiological management.

Unraveling the functional relevance of feedback circuits in the brain

A rich neural network travels in reverse from the brain back to the ear with multiple loops along the way. While we know broadly that these neural systems influence our hearing, how exactly the multiple systems work collaboratively, and their contributions to our listening experience is unclear.

Through series of experiments that test various hypotheses, we aim to unravel the functional relevance of these feedback networks in the brain for human hearing.

Developing protocols for robust auditory transcranial magnetic stimulation

Transcranial magnetic stimulation (TMS) is a neuromodulation technique where a magnetic field is applied to the scalp over a brain region of interest to modulate short-term neural activity. TMS is an FDA approved technique that is used both in research and clinic, eg  for treating depression.

We use TMS to temporarily modulate auditory cortical activity while we study its effects throughout the auditory system. Almost all protocols for performing TMS come from applying TMS to the motor cortex without any tailor-made recommendations for the auditory cortex.

In a first-of-a-kind program we aim to develop TMS protocols that accurately, efficiently, safely, and robustly stimulates the auditory cortex.