An additive blending sound presentation system with air and bone conducted sound

The sound of our voice reaches the inner ear by two paths: the first being air and the second being sound conducted by bones. When you speak, what you hear as your voice is the blending of two signals: one signal comes from the auditory canal and the other signal comes from bone conduction. This paper proposes a new sound presentation system with an additive blending effect with air and bone conducted signals. The system is composed of normal headphones and/plus a bone conduction transducer. The sound quality is evaluated by subjective tests using three kinds of musical sources: Piano, Vocal, and Orchestra. Two experimental conditions are used. One condition is normal headphones as air only (AIR), and the other is normal headphones and a bone conduction transducer simultaneously and in phase (BONE). The subjects select the better quality after comparing AIR and BONE conditions. The result of the experiment shows that the most subjects chose BONE. The proposed system can be used for aged persons or persons with hearing loss.