Disclosed herein, among other things, are apparatus and methods for a hearing assistance device housing for biometric sensing. In various embodiments, a hearing assistance device for a wearer includes a housing customized to conform to a continuous section of an inner portion of an ear of the wearer and to extend radially to one or more edges of a conchal bowl of the ear. The housing is configured to be placed in the inner portion of the ear of the wearer, and a biometric sensor is included on a surface of the housing. According to various embodiments, the housing is configured to maintain contact of the biometric sensor with the inner portion of the ear of the wearer during activity of the wearer, to enhance accuracy of biometric sensing.