Comparing Tinnitus Tuning Curves and Psychoacoustic Tuning Curves

Quantifying Tinnitus Perception Improvement: Deriving the Minimal Clinically Important Difference of the Minimum Masking Level

PURPOSE

Tools that can reliably measure changes in the perception of tinnitus following interventions are lacking. The minimum masking level, defined as the lowest level at which tinnitus is completely masked, is a candidate for quantifying changes in tinnitus perception. In this study, we aimed to determine minimal clinically important differences for minimum masking level.

METHOD

A 3-month tinnitus intervention combining counseling and sound therapy was conducted in 74 participants with chronic tinnitus. Minimum masking levels were measured at baseline and 3 months. The clinical global impression was evaluated at 3 months to measure changes in participants' self-perception of tinnitus. The minimal clinically important difference of the minimum masking level was calculated using anchored-based, effect size, standard error measurement, and receiver operating characteristic curve analysis.

RESULTS

The minimal clinically important difference analysis of the minimum masking level yielded a -5.5 dB SL from the receiver operating characteristic curve, a -8.1 dB SL from the standard error measurement, a -9.2 dB SL from the effect size, and a -10.3 dB SL from the anchor-based analysis. Of these, the minimal clinically important difference value with optimized sensitivity (.704) and specificity (.957) was a -5.5 dB SL, determined using receiver operating characteristic analysis.

CONCLUSIONS

The proposed minimal clinically important difference value of the minimum masking level (-5.5 dB SL) provides a good level of sensitivity and specificity. Therefore, the minimum masking level may be an alternative for measuring changes in tinnitus perception.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.28156229.

Categorization of tinnitus listeners with a focus on cochlear synaptopathy

Tinnitus is a complex and not yet fully understood phenomenon. Often the treatments provided are effective only for subgroups of sufferers. We are presently not able to predict benefit with the currently available diagnostic tools and analysis methods. Being able to identify and specifically treat sub-categories of tinnitus would help develop and implement more targeted treatments with higher success rate. In this study we use a clustering analysis based on 17 predictors to cluster an audiologically homogeneous group of normal hearing participants, both with and without tinnitus. The predictors have been chosen to be either tinnitus-specific measures or measures that are thought to be connected to cochlear synaptopathy. Our aim was to identify a subgroup of participants with characteristics consistent with the current hypothesized impact of cochlear synaptopathy. Our results show that this approach can separate the listeners into different clusters. But not in all cases could the tinnitus sufferers be separated from the control group. Another challenge is the use of categorical measures which seem to dominate the importance analysis of the factors. The study showed that data-driven clustering of a homogeneous listener group based on a mixed set of experimental outcome measures is a promising tool for tinnitus sub-typing, with the caveat that sample sizes might need to be sufficiently high, and higher than in the present study, to keep a meaningful sample size after clustering.

Multidisciplinary Tinnitus Research: Challenges and Future Directions From the Perspective of Early Stage Researchers

Tinnitus can be a burdensome condition on both individual and societal levels. Many aspects of this condition remain elusive, including its underlying mechanisms, ultimately hindering the development of a cure. Interdisciplinary approaches are required to overcome long-established research challenges. This review summarizes current knowledge in various tinnitus-relevant research fields including tinnitus generating mechanisms, heterogeneity, epidemiology, assessment, and treatment development, in an effort to highlight the main challenges and provide suggestions for future research to overcome them. Four common themes across different areas were identified as future research direction: (1) Further establishment of multicenter and multidisciplinary collaborations; (2) Systematic reviews and syntheses of existing knowledge; (3) Standardization of research methods including tinnitus assessment, data acquisition, and data analysis protocols; (4) The design of studies with large sample sizes and the creation of large tinnitus-specific databases that would allow in-depth exploration of tinnitus heterogeneity.

Association Between Tinnitus Pitch and Consonant Recognition in Noise

Purpose Difficulties in speech-in-noise understanding are often reported in individuals with tinnitus. Building on our previous findings that speech-in-noise performance is correlated with subjective loudness of tinnitus, this study aimed to investigate the effect of tinnitus pitch on consonant recognition in noise. Method Pure-tone audiometry and the Quick Speech-in-Noise Test were conducted on 66 participants categorized into four groups by their hearing sensitivity and self-report of tinnitus. Consonant recognition scores at various frequency ranges were obtained at the 5 dB SNR condition of the Quick Speech-in-Noise Test. Participants with tinnitus also completed a tinnitus pitch-matching procedure. Correlation analyses were conducted between tinnitus pitch and the frequency of the worst consonant recognition, and the error rates based on word and sentence position were compared. Results Regardless of hearing sensitivity, tinnitus pitch did not correlate with the frequency of the worst consonant recognition. Sentence-initial word recognition was affected by hearing loss, whereas sentence-final word recognition was not affected by hearing loss or tinnitus. In contrast to individuals with normal hearing, participants with hearing loss varied in full-sentence recognition, with those reporting tinnitus exhibiting significantly higher error rates. Conclusions The findings suggest that the effect of tinnitus on consonant recognition in noise may involve higher level functions more than perceptual characteristics of tinnitus. Furthermore, for individuals with speech-in-noise concerns, clinical evaluation should address both hearing sensitivity and the presence of tinnitus. Future speech-in-noise studies should incorporate cognitive tests and, possibly, brain imaging to parse out the contribution of cognitive factors, such as cognitive control, in speech-in-noise in tinnitus.

The difference in poststimulus suppression between residual inhibition and forward masking

The phenomenon of tinnitus masking (TM) and residual inhibition (RI) of tinnitus are two ways to investigate how external sounds interact with tinnitus: TM provides insight on the fusion between external sound activity and tinnitus related activity while RI provides insight on how the external sound might suppress the tinnitus related activity for a period of time. Differences in masking level between the tinnitus and an external tone with tinnitus characteristics (frequency, loudness) have previously shown a high level of heterogeneity. The difference in poststimulus suppression between the two, that is, residual inhibition for the former, and forward masking for the latter, has never been explored. This study aims to investigate minimum masking levels (MMLs) and minimum residual inhibition levels (MRILs) of tinnitus and of an external tone mimicking tinnitus while using diotic and dichotic noises. Pulsed narrowband noises (1 octave width and centered at 1kHz, frequency of the hearing loss slope, tinnitus frequency) and white noise were randomly presented to 20 tinnitus participants and 20 controls with an external tone mimicking tinnitus (4kHz, intensity level corresponding to tinnitus loudness). The MML values obtained for the masking of tinnitus and for the mimicking external sounds were very similar. On the other hand, the MRILs were significantly different between the tinnitus and the mimicking external sounds within tinnitus participants. They were also different between the tinnitus participants and the controls. Overall, for both within and between comparisons, the MRIL values were much higher to produce a poststimulus suppression for the mimicking sound than for the tinnitus. The results showed no significant differences between the diotic and dichotic conditions. These results corroborate other findings suggesting that the tinnitus-related neural activity is very different from the stimulus-related neural activity. The consequences of this last finding are discussed.