Audiology and hearing

More than five per cent of the world population is living with a disabling hearing loss, with the majority of those individuals living in low- and middle-income countries (LMICs). Yet only a tiny percentage of hearing aids, cochlear implants, and other hearing services are delivered to those in economically deprived regions.

• We work with local partners in LMICs to conduct and analyse epidemiological investigations in order to better understand the needs of their populations.
• We conduct projects which aim to elucidate the benefits and limitations of current service provision in LMICs.
• Our research program encompasses evaluations of the effectiveness and practical limitations of hearing service delivery in LMICs.

The wider goal of this research program is to reduce the barriers to accessing hearing services and rehabilitation globally.

Professor McAlpine’s ARC Laureate Fellowship

Spatial hearing is necessary for locating the source of a sound and critical for communication in noisy listening conditions.

The object of this project is to determine how the mammalian brain, including human listeners, represents sensitivity to interaural time differences, one of the two binaural cues, and how this representation is transformed from the brainstem to the cortex.

Anticipated outcomes include a coherent model of binaural hearing that links cellular, systems and perceptual investigations and an understanding of the human auditory brain that should facilitate novel technologies and interventions to improve hearing function.

Multiple solutions exist to support hard-of-hearing individuals in their communication. The uptake of these solutions, however, is low.

Effectiveness data and cost/benefit analyses are lacking to objectively compare the solutions available. And no standard referral pathway exists throughout the lifetime to support hard-of-hearing individuals and their families in their learning, work and social environments.

We established the Hearing Education Application Research (HEAR) centre – directed by Professor Catherine McMahon – to gather relevant stakeholders and work together towards re-thinking and re-designing our service models and care pathways.

This includes:

• the way that we develop, conduct and interpret research projects
• how reliable knowledge can be shared with, and more easily be used by, clinicians and clients.

Our brain adapts to the stimulation it gets. In the case of hearing, the brain adapts to the sounds, speech, and music it is exposed to.

This adaptation is much more effective at a very young age, during the period when language is developing. In adults who have lost their hearing over time and have used different types of amplifications, it is difficult to estimate the quality and magnitude of speech stimulation their brains have received, and consequently how they have adapted to hearing loss.

In addition, current standard audiology tests are limited in their ability to inform on real-life everyday listening difficulties.

We aim to increase prognostic precision and monitor intervention benefits by

• developing more real-life evaluations of listening abilities
• gaining a better understanding of how the brain adapts to hearing loss, and how it can further adapt to interventions such as hearing aids, cochlear implants and training.

To investigate this, our researchers measure electric and magnetic signals emitted by the brain. In particular we are involved in the development of a unique magnetoencephalography (MEG) prototype device that has been designed to be compatible with cochlear implants, in collaboration with the Centre for Cognition and its Disorder (CCD), and the Kanazawa Institute of Technology (KIT) in Japan.

Our expertise also centres on:

• recreating 3D virtual acoustic environments (such as can be used in the AHH anechoic chamber)
• continuous speech and conversation tests
• using artificial intelligence to develop improved signal processing strategies for hearing devices, to overcome the main challenge of listening in noise.

Many children and adults experience difficulties hearing in a noisy environment, even though their audiogram suggests that they have normal hearing.

While in the past it has been suggested that it could be related to attentional difficulties, no consensus has been reached. Growing evidence suggests that current audiological tests lack the sensitivity to clearly identify what causes these difficulties.

Here we investigate how monaural and binaural auditory processing, cognitive and linguistic skills are affected by noise exposure.

Another aim is to determine whether music training provides a protective mechanism. Concepts such as central gain (when the brain increases a signal it cannot perceive anymore – similar to a phantom limb) are explored. Similarly, the relationship between developmental abilities such as attention, memory, listening and reading is also investigated.

Around seven in 10 people over the age of 65 live with either sight or hearing loss and over two thirds live with depression and other mental illnesses.

Dementia and cognitive impairment steadily rise in prevalence over the age of 65 to the point where almost one third of people at the age of 90 are affected.

Hearing and vision loss interact with cognitive declines to worsen quality of life and reduce function, increasing dependency and care costs. Less than one third of people with sensory/cognitive impairment receive treatment, with marked age, gender, socioeconomic and ethnic inequalities in those who do.

Hearing and vision impairment are markers of risk for cognitive decline and dementia. The hearing loss and mental wellbeing project:

• uses epidemiological modelling to understand relationships between hearing and vision impairment and cognitive decline, dementia, depression and anxiety, as well as modelling the impact of sensory interventions on mental wellbeing outcomes
• works to improve early detection and diagnosis of sensory, cognitive and emotional problems in older people through specially adapted assessment and development of evidence-based clinical guidelines
• works with patients and the public to co-develop and evaluate sensory interventions to improve mental wellbeing outcomes
• provides new information about the economic impact of sensory impairment on mental health and use of health services for older people, and on the cost-effectiveness of sensory support to improve mental wellbeing, quality of life and provision of services.

Our integrated approach to hearing healthcare encompasses world-leading discovery and translational research, excellence in clinical care at our Speech and Hearing Clinic, and a high-quality Master of Clinical Audiology course.

Our researchers are also clinicians, innovators and educators, working collaboratively towards best patient outcomes. This facilitates the development, teaching and implementation of patient-centred, applicable, desirable and cost-effective interventions which are anchored in a rigorous and up-to-date evidence-base.

Master of Clinical Audiology students also engage in an independent research project, providing hands-on experience in the underpinning research that supports Audiology training and services. These projects, amongst others, have supported research in remote Australian communities and developing countries.