Looking for objective correlates between tinnitus and cochlear synaptopathy

  • Chiara Casolani Hearing Systems Section, Department of Health Technology, Technical University of Denmark, DK-2800 Lyngby, Denmark
  • James Michael Harte Interacoustics Research Unit, part of Oticon A/S, DK-2800 Lyngby, Denmark
  • Bastian Epp Hearing Systems Section, Department of Health Technology, Technical University of Denmark, DK-2800 Lyngby, Denmark


Tinnitus is the perception of a sound in the absence of acoustic stimulation. While usually connected to a hearing loss, there exists a subset of tinnitus sufferers with audiologically normal hearing, whose tinnitus was often initiated by a noise trauma. Noise-induced tinnitus might be connected to the noise exposure that leads to a permanent impairment of the hearing system without affecting sensitivity to sound. This is commonly referred to as hidden hearing loss (HHL) and might be connected to cochlear synaptopathy. The hypothesis that HHL is one of the causes underlying tinnitus is based on suppositions that both phenomena are related to deafferentation of auditory nerve fibres and related central gain adjustments. To investigate this connection, a screening procedure consisting of high frequency audiometry (HFA), tinnitus likeness spectrum and loudness, psychophysical tuning curves (PTC) and tinnitus masking curves (TMC), adaptive categorical loudness scaling, and middle-ear muscle reflex test was developed. Pilot results show that all measurements can be completed within a short time frame, due to a Bayesian procedure being adopted to measure HFA, PTC and TMC. These procedures may contribute to investigating the connection between tinnitus and HHL with a large number of outcome measures. This connection will provide important insights toward the development of better diagnoses and treatment methods.


Baracca, G., Del Bo, L., and Ambrosetti, U. (2011). “Tinnitus and hearing loss,” Textbook of Tinnitus, Springer New York, 285–291, doi: 10.1007/978-1-60761- 145-535.

Fournier, P., Wrzosek, M., Paolino M., Paolino F., Quemar A., and Norena A. (In press). “Comparing the patterns of tuning for tinnitus and tinnitus-like sound,” Trends Hear.

Furman, A.C., Furman, A.C., Kujawa, S.G., Kujawa, S.G., and Liberman, M.C. (2013). “Noise-induced cochlear neuropathy is selective for fibers with low spon- taneous rates,” J. Neurophysiol., 110(3), 577–586, doi: 10.1152/jn.00164.2013.

Hein, T., Hatzopoulos, S., Skarzynski, P., and Colella-Santos, M. (2017). “Wideband Tympanometry,” Advances in Clinical Audiology, 29-42, doi: 10.5772/67155.

Kluk, K., and Moore, B.C.J. (2005). “Factors affecting psychophysical tuning curves for hearing-impaired subjects with high-frequency dead regions,” Hearing Res., 200(1-2), 115–131, doi: 10.1016/j.heares.2004.09.003.

Kujawa, S.G., and Liberman, M.C. (2015). “Synaptopathy in the noise-exposed and aging cochlea: Primary neural degeneration in acquired sensorineu- ral hearing loss,” Hearing Res., 330(Part B, Sp. Iss. SI), 191–199, doi: 10.1016/j.heares.2015.02.009.

Lobarinas, E., Salvi, R., and Ding, D. (2016). “Selective Inner Hair Cell Dysfunction in Chinchillas Impairs Hearing-in-Noise in the Absence of Outer Hair Cell Loss,” J. Assoc. Res. Oto., 17(2), 89–101, doi: 10.1007/s10162-015-0550-8.

Schaette, R., and McAlpine, D. (2011). “Tinnitus with a normal audiogram: Physiological evidence for hidden hearing loss and computational model,” J. Neurosci., 31(38), 13452–13457, doi:10.1523/jneurosci.2156-11.2011.

Schlittenlacher, J., Turner, R.E., and Moore, B.C.J. (2018). “Audiogram estimation using Bayesian active learning,” J. Acoust. Soc. Am., 144(1), 421–430, doi: 10.1121/1.5047436.

Schmuziger, N., Probst, R., and Smurzynski, J. (2004). “Test-Retest Reliability of Pure-Tone Thresholds from 0.5 to 16 kHz using Sennheiser HDA 200 and Etymotic Research ER-2 Earphones,” Ear Hear., 25(2), 127–132, doi: 10.1097/01.aud.0000120361.87401.c8.

Wojtczak, M., Beim, J.A., and Oxenham, A.J. (2017). “Weak middle-ear-muscle reflex in humans with noise-induced tinnitus and normal hearing may reflect cochlear synaptopathy,” eNeuro, 4(6), e0363–17.2017, e0363–17.2017, doi: 10.1523/eneuro.0363-17.2017.

How to Cite
Casolani, C., Harte, J., & Epp, B. (2020). Looking for objective correlates between tinnitus and cochlear synaptopathy. Proceedings of the International Symposium on Auditory and Audiological Research, 7, 421-428. Retrieved from https://proceedings.isaar.eu/index.php/isaarproc/article/view/2019-49
2019/5. Other topics in auditory and audiological research