aMpLiTuDe MoDuLaTeD noise for tinnitus suppression in tonal and noise-like tinnitus

Abstract

Background: Acoustic stimulation offers a potential treatment approach for tinnitus but also insights in its basic mechanisms by short-term tinnitus suppression called residual inhibition (RI). The effects of RI were found to be depending on intensity, length or sound types covering the individual tinnitus characteristics. In patients with tonal tinnitus RI was increased with amplitude modulated (AM) pure tones at the individual tinnitus frequency while the effects of modulated noise sounds have not been systematically researched.Objectives: The aim of the present study was to investigate whether in patients with noise-like tinnitus RI can be increased by AM noise-like stimuli according to the individual tinnitus frequency range.Methods: For this purpose the individual tinnitus characteristics (noise-like and tonal tinnitus) were assessed via customizable noise-band matching, in order to generate bandpass filtered stimuli according to the individual tinnitus sound (individualized bandpass filtered sounds; IBP). Subsequent, various stimuli differing in bandpass filtering and AM were tested with respect to their potential to induce RI. Patients were acoustically stimulated with seven different types of stimuli for three minutes each and had to rate the loudness of their tinnitus after each stimuli.Results: Results indicate a general efficacy of noise stimuli for the temporary suppression of tinnitus, but no significant differences between AM and unmodulated IBP. Significantly better effects were observed for the subgroup with noise-like tinnitus (n=14), especially directly after stimulation offset. Conclusions:The study at hand provides further insights in potential mechanisms behind RI for different types of tinnitus. Beyond that, derived principles may qualify for new or extend current tinnitus sound therapies.Chronic subjective tinnitus is defined as the permanent perception of a sound such as ringing or 1 hissing in the absence of an external or internal source of noise. Approximately 10-15% of the 2 population in industrial countries experience this phantom sound [Langguth et al., 2013; Erlands-3 son and Dauman, 2013; Heller, 2003; Hall et al., 2011]. Causes for the development of tinnitus are 4 divergent and not completely understood, though most commonly tinnitus occurs towards cochlear 5 damages due to noise trauma [Langguth et al., 2013]. In the majority of cases, the perceived tin-6 nitus pitch is in accordance with the frequency spectrum of hearing loss (HL) [Basile et al., 2013; 7 Roberts et al., 2008]. As a consequence of decreased or absent auditory input and the subsequent 8 deficiency of neural input, maladaptive pathological changes in the auditory pathway are formed, 9 which lead to the perception of a "phantom sound" defined as tinnitus [Eggermont, 2007; Egger-10 mont and Tass, 2015; Eggermont and Roberts, 2012]. Neurophysiological investigations were able 11 to demonstrate hyperactivity in auditory brain areas [Farhadi et al., 2010; Folmer, 2007] as well as 12 aberrant oscillatory brain...

Neurophysiological correlates of residual inhibition in tinnitus: Hints for trait-like EEG power spectra

“…Interestingly, stimulus IBP was evaluated with the lowest tolerability as indicated by the highest arousal and lowest valence ratings. This finding is contrary to one of our previous experiments which reports low arousal and high valence ratings for IBP [Schoisswohl et al, 2019].…”

“…Generally, about 50 to 90% of the studied individuals report some level of tinnitus suppression after acoustic stimulation (e.g., [Neff et al, 2017;Schoisswohl et al, 2019;Fournier et al, 2018;Kahlbrock and Weisz, 2008;Sedley et al, 2012]). Given the skewed distribution of RI responses on the group level in previous and this study as well as the need for a reliable threshold for strong tinnitus suppression, we opted to define a reduction in tinnitus of 50% after acoustic stimulation as the threshold for the responder classification akin to [Kahlbrock and Weisz, 2008].…”

“…Since that time several experiments already examined the impact of various auditory stimulation techniques on RI. These vary from simple white noise (WN) or pure tones, to the application of specific filters or modulation rates, up to the combination of both modulation techniques applied to WN [Henry et al, 2013;Fournier et al, 2018;Roberts et al, 2006Roberts et al, , 2008Tyler et al, 2014;Reavis et al, 2012;Bates et al, 2015;Neff et al, 2017Neff et al, , 2019bSchoisswohl et al, 2019]. It has been suggested that stimulation intensity, duration, specific modulations as well as stimuli including the individual tinnitus frequency (ITF) facilitate short-term acoustic tinnitus suppression.…”

The state of the art of sound therapy for subjective tinnitus in adults

“…Compared with patients with tonal tinnitus, patients with noise-like tinnitus saw significantly better treatment effects, especially directly after stimulation termination. 36 In addition to the influence of individual factors, the type of modulated sound also has an effect on the efficacy of the therapy. The clinical trial by Reavis et al provided evidence that low-rate amplitude-modulated tones with a high carrier frequency in the tinnitus pitch range were the most effective at reducing tinnitus loudness.…”

Comparison of Sudden Sensorineural Hearing Loss with Tinnitus and Short-Term Tinnitus

“…The acoustic therapy of tinnitus, a method suppressing tinnitus through using sound to change the perception and response of tinnitus, includes special flame wave music therapy centered on tinnitus frequency; neuromusical therapy; neural desynchronization modulation and modulate the sound [6][7][8], etc. The results of various studies on the efficacy of acoustic therapy vary greatly, ranging from 21 to 67%.…”