Loss of inner-ear nerve connections and how it affects hearing test results
Official title: Cochlear synaptopathy and audiometric measures from human temporal-bone cases of sensorineural hearing loss
Funded at Massachusetts Eye and Ear Infirmary · NIH-11158995 · Data updated 2026-11-12
This project looks at donated human inner ears to learn how loss of nerve connections affects hearing and speech understanding in people with sensorineural hearing loss.
Quick facts
| Grant type | NIH-funded research |
|---|---|
| Study type | NIH-funded research |
| Funding institution | Massachusetts Eye and Ear Infirmary NIH-funded |
| Lab location | 1 site (Boston, United States) |
| Project start | August 2, 2017 |
| Project end | July 31, 2027 |
| Funding year | 2025 |
| Award (this year) | $575,200 |
| NIH project number | 5P50DC015857-09 |
| Project ID | NIH-11158995 on NIH RePORTER |
Who could benefit from this research
✓Could help
Ideal candidates are people with sensorineural hearing loss — especially those with a history of noise exposure, ototoxic drugs, sudden hearing loss, or Ménière’s disease — who would consider donating their temporal bones after death or joining related clinical efforts.
✕Less likely to help
People whose hearing problems are purely conductive (middle- or outer-ear conditions) or unrelated to hair-cell or nerve damage are unlikely to benefit directly from these findings.
What this research studies
Because the inner ear can't be biopsied, researchers examine donated post-mortem temporal bones under a microscope to see changes at the cell and nerve level. They compare patterns of hair cell loss and auditory nerve (synapse) loss with patients' past hearing tests and speech scores to understand why people with similar audiograms can hear differently. The work builds on earlier findings that nerve loss can outpace hair cell loss and is worse after noise exposure, and it will expand to include causes like ototoxic antibiotics, chemotherapy, sudden hearing loss, and Ménière's disease. By using archived human specimens and statistical models, the team aims to link microscopic damage to real-world hearing problems such as trouble understanding speech and tinnitus.
Why it matters
Potential benefit: If successful, this work could help doctors detect hidden nerve damage and guide treatments to improve speech understanding and reduce tinnitus for people with sensorineural hearing loss.
How similar studies have gone: Prior animal studies and earlier human temporal bone analyses from this group have shown similar patterns of nerve loss and links to speech understanding, so this work builds on promising prior results.
Where this research is happening
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Massachusetts Eye and Ear Infirmary
Boston, United States Active
Researchers
- Principal investigator: Liberman, M. Charles — Massachusetts Eye and Ear Infirmary
- Study coordinator: Liberman, M. Charles
Related research
Other NIH-funded projects on the same topics.
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Understanding why phantom sounds and intolerance to sounds happen after hearing loss
This grant investigates why some adults with hearing loss experience tinnitus, hyperacusis, and trouble ignoring background noise, and how brain changes relate to these symptoms.
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Biomarkers linked to cochlear nerve damage in adults with sensorineural hearing loss
A project to find biological markers of cochlear nerve damage and see how they relate to hearing problems like difficulty hearing in noise and tinnitus in adults with hearing loss.
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Cochlear nerve connections and hearing loss in human temporal bones
A large, patient-facing research effort analyzes how nerve connections in the inner ear deteriorate in people with sensorineural hearing loss by studying post-mortem human temporal bones.
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Cochlear nerve disease and how it affects hearing in models of hearing loss
This grant studies how damage to the nerves of the ear happens and how it affects hearing in noisy places, using animal models to inform future human therapies.
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Sensorineural hearing loss and how it affects understanding speech
This project explores why people with similar hearing loss have different abilities to understand speech, especially in noisy places, and aims to uncover the brain and ear mechanisms behind these differences.
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Understanding why some people with hearing loss can’t understand speech in noise
This grant studies why some people with hearing loss can’t understand speech in noisy environments, even when they can hear it, to identify new ways to help them hear and understand better.
About this research
- This is an active NIH-funded research project — typically early-stage science, not a clinical trial accepting patient enrollment.
- Some NIH-funded labs run parallel clinical studies or seek volunteers for related work. To check, contact the principal investigator or institution listed above.
- For full project details, budget, and progress reports, visit the official NIH RePORTER page.