Tinnitus is a prevalent auditory disorder that frequently co-occurs with hearing loss. It is suggested that tinnitus might have negative impact on speech perception. However, studies thus far have not been able to disentangle tinnitus, hearing loss, and speech in noise intelligibility. We therefore investigated whether there is an association between tinnitus and speech understanding in noise, independent of hearing loss.
Of 4,211 participants from the population-based Rotterdam Study (mean age 67.8 [SD 8.9], 57.3% female) data was available on tinnitus, pure-tone audiometry, and digits in noise test. We compared the speech reception threshold in noise (SRTn) in participants with and without tinnitus for the whole population as well as for subgroups stratified for average hearing threshold in 10-dB strata. Additionally, we regressed tinnitus on SRTn with a multivariable regression model, adjusting for sex, age, highest achieved education, and cognitive function.
Participants with tinnitus (20.8%) had a higher SRTn (−3.6 dB [SD 3.7] versus −4.6 dB [SD 3.1]). This difference remained only in the subgroups of participants with hearing loss, between 0.6 and 0.8 dB difference in the SRTn for the different subgroups. In the fully adjusted model tinnitus was associated with 0.2 dB (95% CI 0.00, 0.39) SRTn increase.
We have shown that tinnitus is associated with speech intelligibility in noise, but it is a small effect, only found in people with co-occurring hearing loss.