Double tinnitus in a single ear

Tinnitus characteristics in patients with hyperacusis and vertigo (including Ménière's disease) vs. hyperacusis alone

INTRODUCTION AND OBJECTIVES

To compare clinical and psychoacoustic tinnitus characteristics in patients with the comorbidity of hyperacusis, hyperacusis and vertigo, and with Ménière's disease (MD).

MATERIALS AND METHODS

Three hundred and twenty-nine tinnitus patients underwent audiological and otoneurological evaluation. Records of 94 individuals younger than 65 years, 40 women and 54 men (mean age 41.8, range 24-64 years), who complained of tinnitus and hyperacusis, were analyzed. One hundred and thirty-one ears with tinnitus were identified: 67 in the group of patients with tinnitus and hyperacusis (group 1; 41 patients); 28 in the group fulfilling criteria of MD diagnosis (group 2; 28); and 36 in the group with tinnitus, hyperacusis and typical symptoms of vertigo (group 3; 25).

RESULTS AND CONCLUSIONS

Mean value of interaural difference in canal paresis in group 1 was 6.3%; in group 2: 23.7%; and in group 3: 25.9%; p<.001. Mean tinnitus pitch value was significantly lower in group 3 (1679Hz; SD=1139) and group 2 (2250Hz; SD=1162) compared to group 1 (4538Hz; SD=3123; p=.012). Values of tinnitus intensity and other characteristics did not significantly differ between the groups. Tinnitus and hyperacusis were most frequently preceded by acoustic trauma. Tinnitus coinciding with hyperacusis and vertigo was observed in patients after head trauma. Mean tinnitus pitch was lower in the groups of patients with hyperacusis and peripheral labyrinthine lesion than in tinnitus sufferers with hyperacusis alone. Tinnitus sufferers with low tinnitus pitch should undergo vestibular system evaluation. Hyperacusis and vertigo are likely comorbidities in tinnitus patients after head trauma. Hyperacusis may coincide in tinnitus patients after head trauma.

Comparing Tinnitus Tuning Curves and Psychoacoustic Tuning Curves

Tinnitus masking patterns have long been known to differ from those used for masking external sound. In the present study, we compared the shape of tinnitus tuning curves (TTCs) to psychophysical tuning curves (PTCs), the latter using as a target, an external sound that mimics the tinnitus characteristics. A secondary goal was to compare sound levels required to mask tinnitus to those required to mask tinnitus-mimicking sounds. The TTC, PTC, audiometric thresholds, tinnitus pitch, and level matching results of 32 tinnitus patients were analyzed. Narrowband noise maskers were used for both PTC and TTC procedures. Patients were categorized into three groups based on a combination of individual PTC-TTC results. Our findings indicate that in 41% of cases, the PTC was sharp (V shape), but the TTC showed a flat configuration, suggesting that the tinnitus-related activity in that subgroup does not behave as a regular stimulus-induced activity. In 30% of cases, V-shape PTC and TTC were found, indicating that the tinnitus-related activity may share common properties with stimulus-induced activity. For a masker centered at the tinnitus frequency, the tinnitus was more difficult to mask than the mimicking tone in 72% of patients; this was particularly true for the subset with V-shape PTCs and flat TTCs. These results may have implications for subtyping tinnitus and acoustic therapies, in particular those targeting the tinnitus frequency.