Disclosed herein, among other things, are apparatus and methods for micromachined ultrasonic transducer switches for hearing assistance devices. In various embodiments, a hearing assistance device includes a housing, hearing assistance electronics within the housing, and a micromachined ultrasonic transducer connected to the hearing assistance electronics. The micromachined ultrasonic transducer is configured to switch upon detection of proximity or touch by the wearer. In various embodiments, the micromachined ultrasonic transducer includes one ultrasonic transmitter and one ultrasonic receiver. The micromachined ultrasonic transducer is adapted to control one or more functions of the hearing assistance electronics, in various embodiments.