Its Management by Sound Therapy

Tinnitus is the perception of sound occurring without an external stimulus. Sound therapy is one of the most effective treatment techniques that have been employed by clinicians. To account for mechanisms of tinnitus generation and the clinical effects of sound therapy from the viewpoint of neural engineering, the authors have proposed a conceptual neural oscillator model with plasticity for the human auditory system. In this study, the authors found that this model has a bistable state, i.e., a condition where a stable oscillatory state and a stable non-oscillatory equilibrium state coexist at a certain parameter region. It was also found that the oscillation can be inhibited by supplying sinusoidal or random stimuli, which was hypothesized as sound for treatment of tinnitus, in this model. Through numerical simulations, the authors discovered that adequate noise stimulus can inhibit the oscillation. By hypothesizing that the oscillation and the equilibrium correspond to generation and inhibition of tinnitus, respectively, it can be stated that these phenomena could explain the fact that the human auditory system temporarily halts perception of tinnitus following sound therapy. This paper describes dynamical properties of the model and inhibition of the oscillation for sinusoidal stimulus and a kind of noise stimulus, which corresponds to the sound in the treatment of tinnitus.