Fundamentals of human hearing: from basic cochlear processing to cortical representations
Lead Research Organisation:
University of Nottingham
Department Name: School of Medicine
Abstract
Hearing loss is a prevalent and growing health problem that can cause considerable life burden, inhibiting social and work activities and lowering mood, and has recently been identified as a major risk factor for developing degenerative brain diseases, such as Alzheimer's, in later life.
Hearing loss is diagnosed by a reduction in the patient's ability to hear faint sounds. However, in everyday life, inability to hear faint sounds is not usually the patient's primary problem. Rather, patients usually complain about difficulties hearing in noisy environments (e.g., following a conversation in a noisy pub), and these difficulties persist even when wearing a hearing aid. In addition, some patients also complain about experiencing certain everyday sounds as excruciatingly loud, and many hearing-impaired patients experience a continuous, and often irritating, ringing or hissing sound in the ear or head, referred to as "tinnitus". These problems are currently untreatable and their causes remain largely unknown.
In this research programme, we will investigate the idea that they arise as a result of changes in the way in which sounds are processed and represented within the brain. We will focus on the highest-level, most sophisticated part of the brain referred to as "cortex", which is particularly well-developed in humans. Using cutting-edge brain imaging technologies, we will develop methods for mapping cortical sound responses at a sub-millimetre spatial scale, and tracing their temporal dynamics with millisecond accuracy. Using these methods, we will then investigate the exact mechanisms by which cortical sound processing is altered as a result of hearing loss.
Insights gained from this programme may lead to the development of better, more individualized treatment options for hearing impairment, and help to understand how hearing loss impacts brain health.
Hearing loss is diagnosed by a reduction in the patient's ability to hear faint sounds. However, in everyday life, inability to hear faint sounds is not usually the patient's primary problem. Rather, patients usually complain about difficulties hearing in noisy environments (e.g., following a conversation in a noisy pub), and these difficulties persist even when wearing a hearing aid. In addition, some patients also complain about experiencing certain everyday sounds as excruciatingly loud, and many hearing-impaired patients experience a continuous, and often irritating, ringing or hissing sound in the ear or head, referred to as "tinnitus". These problems are currently untreatable and their causes remain largely unknown.
In this research programme, we will investigate the idea that they arise as a result of changes in the way in which sounds are processed and represented within the brain. We will focus on the highest-level, most sophisticated part of the brain referred to as "cortex", which is particularly well-developed in humans. Using cutting-edge brain imaging technologies, we will develop methods for mapping cortical sound responses at a sub-millimetre spatial scale, and tracing their temporal dynamics with millisecond accuracy. Using these methods, we will then investigate the exact mechanisms by which cortical sound processing is altered as a result of hearing loss.
Insights gained from this programme may lead to the development of better, more individualized treatment options for hearing impairment, and help to understand how hearing loss impacts brain health.
Technical Summary
Neurophysiological research has suggested that, in animals, peripheral hearing loss can lead to profound changes in cortical auditory processing, causing large-scale reorganization in primary cortical tonotopic maps and down-regulating contextual and time-dependent suppression of cortical responses through lateral inhibition and neuronal adaptation. Such changes, if they also occur in humans, might explain common, but as yet untreatable consequences of hearing loss, such as hearing difficulty in noisy environments, hyperacusis and tinnitus. This research programme is aimed at testing the extent to which these changes occur in humans, and developing efficient and unbiased tools for measuring them in individual patients. In order to measure cortical tonotopic reorganization, we will first formulate an integrated model of human auditory cortex organization based on functional and structural MRI data measured at ultra-high field strengths (7T). Based on this model, we will develop a set of operational tools for delineating auditory areal borders in individual living brains (in-vivo parcellation). Hearing loss-related changes in contextual and time-dependent suppression will be measured with EEG. For that, we will develop a new method of estimating EEG sources from different cortical areas defined by tonotopic fMRI mapping, which will reduce inter-individual variability and establish a direct relationship between EEG and MRI results.
Planned Impact
Audiological patients may present with disparate problems, even though their audiometric, or hearing, thresholds are similar: some may suffer from severe tinnitus, whilst others hardly notice any tinnitus; some may feel that their hearing has become excessively loud, whereas others may feel that they don't hear enough. This research aims to uncover the neurological mechanisms by which these differences might come about. This will help audiological patients and their health professionals appreciate and cope with their problems better, and, in the longer run, may lead to the development of better treatment options.
Publications
Besle J
(2019)
Is Human Auditory Cortex Organization Compatible With the Monkey Model? Contrary Evidence From Ultra-High-Field Functional and Structural MRI.
in Cerebral cortex (New York, N.Y. : 1991)
Krumbholz K
(2020)
Automated extraction of auditory brainstem response latencies and amplitudes by means of non-linear curve registration.
in Computer methods and programs in biomedicine
Persic D
(2020)
Regulation of auditory plasticity during critical periods and following hearing loss.
in Hearing research
De Boer J
(2022)
Could Tailored Chirp Stimuli Benefit Measurement of the Supra-threshold Auditory Brainstem Wave-I Response?
in Journal of the Association for Research in Otolaryngology : JARO
De Boer J
(2020)
Noise-Induced Changes of the Auditory Brainstem Response to Speech-a Measure of Neural Desynchronisation?
in Journal of the Association for Research in Otolaryngology : JARO
Description | NIHR Biomedical Research Centres (BRC) Competition |
Amount | £23,298,874 (GBP) |
Funding ID | NIHR203310 |
Organisation | University of Nottingham |
Sector | Academic/University |
Country | United Kingdom |
Start | 12/2022 |
End | 11/2027 |
Description | TIN-ACT |
Amount | € 2,700,000 (EUR) |
Funding ID | H2020 MSCA ITN 2017 |
Organisation | European Commission H2020 |
Sector | Public |
Country | Belgium |
Start | 09/2018 |
End | 09/2021 |
Title | Automated extraction of ABR latencies and amplitudes |
Description | This is a computational method to extract latencies and amplitudes of auditory brainstem responses using non-linear curve registration. The methodology is described in a Computer Methods and Programs in Biomedicine publication and the code has been made available on github. |
Type Of Material | Model of mechanisms or symptoms - human |
Year Produced | 2020 |
Provided To Others? | Yes |
Impact | This method provides a simple and efficient way of evaluating supra-threshold auditory brainstem responses when manual evaluation would be too unreliable or time-consuming. |
URL | https://github.com/mszkk3/Non-linear-ABR-registration- |
Description | Effect of hearing-aid use and auditory-cognitive training on speech-cue weighting for adults with hearing loss |
Organisation | National Institute for Health Research |
Department | NIHR Nottingham Biomedical Research Centre |
Country | United Kingdom |
Sector | Academic/University |
PI Contribution | Co-investigator; will advise and help with EEG data collection, analysis and dissemination. |
Collaborator Contribution | Data collection, analysis and dissemination. |
Impact | No outcomes yet. Project is starting in April. |
Start Year | 2024 |
Description | Investigating the impact of auditory sensory deprivation on brain structural integrity using the UK Biobank imaging data. |
Organisation | University of Nottingham |
Country | United Kingdom |
Sector | Academic/University |
PI Contribution | Intellectual input & data analysis. |
Collaborator Contribution | Intellectual input & data provision (through UK Biobank collaborator license). |
Impact | No outputs yet. |
Start Year | 2021 |
Description | Neurochemical studies of tinnitus and hearing loss using magnetic resonance (MR) imaging |
Organisation | University of Nottingham |
Department | School of Medicine |
Country | United Kingdom |
Sector | Academic/University |
PI Contribution | Intellectual input, studentship supervision |
Collaborator Contribution | Intellectual input, studentship supervision |
Impact | This collaboration has so far produced one publication (Simoes et al. "Multidisciplinary Tinnitus Research: Challenges and Future Directions From the Perspective of Early Stage Researchers" Front. Aging Neurosci. 2021 doi: 10.3389/fnagi.2021.647285), as well as posters at Human Brain Mapping and ISMRM. |
Start Year | 2018 |
Description | Transcranial direct current stimulation (tDCS) for tinnitus - effects of multiple treatment sessions: a randomised-controlled pilot study |
Organisation | National Institute for Health Research |
Department | NIHR Nottingham Biomedical Research Centre |
Country | United Kingdom |
Sector | Academic/University |
PI Contribution | Co-investigator; will advise and help with EEG data collection, analysis and dissemination. |
Collaborator Contribution | Data collection, analysis and dissemination. |
Impact | Project is starting in June. No outputs yet. |
Start Year | 2024 |
Description | Ultra - high resolution 7 Tesla fMRI, pushing the resolution to cortical layers: implications for understanding brain plasticity |
Organisation | University of Nottingham |
Department | School of Physics and Astronomy |
Country | United Kingdom |
Sector | Academic/University |
PI Contribution | Intellectual input, studentship supervision |
Collaborator Contribution | Intellectual input, studentship supervision |
Impact | Poster presentations at Human Brain Mapping and ISMRM. |
Start Year | 2018 |
Description | Public science fair |
Form Of Engagement Activity | Participation in an activity, workshop or similar |
Part Of Official Scheme? | No |
Geographic Reach | Regional |
Primary Audience | Public/other audiences |
Results and Impact | In this event, scientists from the University of Nottingham and Nottingham Trent University and also local organisations showcased their research in a publicly accessible and family-friendly manner. The event attracted a total of 856 participants. |
Year(s) Of Engagement Activity | 2022 |
URL | https://www.nottingham.ac.uk/home/featureevents/2022/science-in-the-park-2022.aspx |
Description | Themed stand, about the human auditory system, at the Malvern Festival of Innovation. |
Form Of Engagement Activity | Participation in an activity, workshop or similar |
Part Of Official Scheme? | No |
Geographic Reach | National |
Primary Audience | Public/other audiences |
Results and Impact | We had a stand at the family day and show of the Festival of Innovation. Our stand included family-friendly activities, such as an exploration of how loud sounds are and what sound is measured in, how the auditory system processes sound, what hearing loss sounds like and what we can do to help people with hearing loss. Our demos stimulated and engaged many visitors, and most of them reported increased interest in our area of research. |
Year(s) Of Engagement Activity | 2019 |
URL | https://www.festival-innovation.com/ |