A Model-Based Placement Strategy for a Nearby External Microphone for Speech Enhancement in Hearing Aids

A theoretical acoustic model of the human torso is proposed in this paper. The human torso is approximated with an infinitely long rigid cylinder and the scattering due to an incident plane wave is modeled. The derivation of the acoustic model is first discussed, along with its limitations. The theoretical scattering patterns are compared to empirical measurements. A placement strategy using the acoustic model is also proposed for nearby hearing aid microphone accessories such that the external microphone maximally benefits from the body shielding noise from the back hemisphere.