Comparison of outer ear models used in sound therapy for the management of tinnitus

Tinnitus is an unusual sensation of hearing perceived without direct sound source. Given the multiplicity of management methods, a work of schematization of the most used therapies; i.e. Tinnitus Retraining Therapy (TRT), Cognitive and behavioral therapy (CBT), and Phase-out” sound therapy (POST) is led based on the Jastreboff model. Human ear models can be used to predict therapy effectiveness. Therefore, we presented three different models (an electric model, an acoustic model and a finite element model) which we then compared by applying them to two external ear shapes. The first is considered to have an auditory canal of uniform section and the second approaches the real shape of the external ear (variable section). The finite element (FE) model gives the most accurate results seeing that it allows to approach the real dimensions of the outer ear. The acoustic model gives results with a maximum deviation of 7,2 percent compared to the FE model with reduced computation time and simpler manner. The electric model is best suited if we consider the outer ear as a tube of uniform section closed at its end.