Evaluation of the Mixing Point in Tinnitus Sound Therapy by a Psychoacoustic Matching Protocol with a Digital Tinnitus Evaluation System

Abstract

Directive counseling and sound therapy have been reported to effectively alleviate tinnitus suffering. Without objective evaluation, researchers doubt the real effect of sound therapy. This study was designed to evaluate the frequency and intensity of the theoretical ‘mixing point’ (MP) in sound therapy and to investigate its relationship with the minimal masking level (MML) of tinnitus. The tinnitus tones of 133 patients were successfully matched in frequency (dominant in 4–10 kHz) and loudness (83.09 ± 12.04 dB) using a psychoacoustic matching protocol and a newly designed tinnitus evaluation system. The matching rate was 83%. The relationship between the MP and MML is described by a linear regression equation: MP = 0.90 × MML + 1.98 (r² = 0.82, p < 0.0001). The results of matching and correlation analysis confirmed the consistency of the MP in sound therapy. The psychoacoustic characteristics of tinnitus can be objectively evaluated with our matching protocol and evaluation system.

An Adaptation Level Theory of Tinnitus Audibility

“…The lowest combined tinnitus and stimulus annoyance a simple embodiment of Jastreboff (principle 5) occurred at 34% of the range from threshold to MML. The research findings of Searchfield et al (2002) suggest ideal therapeutic levels lower than Huang et al (2006) and the theoretical function of Jastreboff (1999b). The experimental differences may be explained, at least in part, by the presentation methods to obtain mixing point (randomized; Searchfield et al, 2002 versus descending sequence from MML; Huang et al, 2006).…”

“…Trials of masking versus TRT (Henry et al, 2006) and the neuromonics treatment (Tavora-Vieira et al, 2011) suggest that some people achieve greater reductions in severity with higher of levels of sound initially, with longer-term benefits with a lower level of sound. The relationship between the mixing point and MML have been examined in short-term laboratory-based evaluations (Searchfield et al, 2002; Huang et al, 2006). Huang et al (2006) determined that the mixing point occurred at approximately 90% of MML.…”

“…The relationship between the mixing point and MML have been examined in short-term laboratory-based evaluations (Searchfield et al, 2002; Huang et al, 2006). Huang et al (2006) determined that the mixing point occurred at approximately 90% of MML. Searchfield et al (2002) were able to identify a reliable mixing point in 63% (17 of 27) of participants at an average level of 18 dB SL (range 1–43.5 dB SL, 10–97.5% of the dynamic range between threshold and MML).…”

Relationships among Speech Perception, Self-Rated Tinnitus Loudness and Disability in Tinnitus Patients with Normal Pure-Tone Thresholds of Hearing

“…Audiologic evaluation comprised pure-tone audiometry, tympanometry, acoustic reflex thresholds/decay, and otoacoustic emission test. Tinnitus evaluation includes a psychoacoustic tinnitus matching protocol which is arranged in a sound-proof room equipped with a digital tinnitus evaluation system [12] . Frequencies of pure-tone thresholds were 250, 500, 1,000, 2,000, 4,000, 8,000 Hz in air conduction and 500, 1,000, 2,000, 4,000 Hz in bone conduction.…”

Characterisitics and maskability of self-reported tinnitus in Adult Nigerians

“…The knowledge obtained from these led to use of tinnitus masking as a therapeutic tool and to further studies on tinnitus measurement. This has further strengthen tinnitus assessment and has led to development of psychoacoustic matching protocol 4 . With etiology largely unknown, and several factors believed to be associated with development of different types of tinnitus, research on tinnitus has focused mainly on moderators 5 and mediators 6 of tinnitus distress.…”