Relationship between tinnitus pitch and edge of hearing loss in individuals with a narrow tinnitus bandwidth

Abstract

Objective: Psychoacoustic measures of tinnitus, in particular dominant tinnitus pitch and its relationship to the shape of the audiogram, are important in determining and verifying pathophysiological mechanisms of the condition. Our previous study postulated that this relationship might vary between different groups of people with tinnitus. For a small subset of participants with narrow tinnitus bandwidth, pitch was associated with the audiometric edge, consistent with the tonotopic reorganization theory. The current study objective was to establish this relationship in an independent sample.

Design: This was a retrospective design using data from five studies conducted between 2008 and 2013.

Study sample: From a cohort of 380 participants, a subgroup group of 129 with narrow tinnitus bandwidth were selected.

Results: Tinnitus pitch generally fell within the area of hearing loss. There was a statistically significant correlation between dominant tinnitus pitch and edge frequency; higher edge frequency being associated with higher dominant tinnitus pitch. However, similar to our previous study, for the majority of participants pitch was more than an octave above the edge frequency.

Conclusions: The findings did not support our prediction and are therefore not consistent with the reorganization theory postulating tinnitus pitch to correspond to the audiometric edge.

Trial registration: ClinicalTrials.gov NCT02095262.

Keywords: Audiogram; audiometric edge; multiple regression; narrow bandwidth; tinnitus pitch.

Figure 1.

Association between hearing level and the dominant tinnitus pitch. Top and middle panels illustrate audiometric thresholds for all 129 patients in the steeper (top panel) and less-steep (middle panel) ear with median shown by the solid black line. Bottom panel shows the distribution of the dominant tinnitus pitch derived from the similarity ratings.

Figure 2.

Scatterplots examining the relationship between dominant tinnitus pitch and the edge of the hearing loss in the steeper (top graph) and less-steep ear (bottom graph) in all participants with narrow tinnitus bandwidth.

Figure 3.

Comparison of Pearson's correlation coefficients (dots) and confidence intervals (lines) in the current study and in Sereda et al (2011). Lines shown in black represent the subgroup of participants reporting a narrow tinnitus bandwidth. Lines shown in grey represent the whole recruited sample.

Figure 4.

Scatterplots examining the relationship between dominant tinnitus pitch and degree of the hearing loss in the steeper (top graph) and less-steep ear (bottom graph).