An activation accessory for a controlled device, comprising: a vibration motor; a wearable module being supported in a mount of a headset, the headset comprising a frame for wearing over the ears of a wearer, wherein the frame comprises temple pieces, the wearable module including a Hall effect sensor and further including an elongated member and a buckle to slidably mount the wearable module on one of the temple pieces of the frame so as to extend from the temple piece when the frame is worn by the wearer, the wearable module positionable to allow the Hall effect sensor to detect relaxed and clenched conditions of the wearer's masseter muscles when the frame is worn by the wearer, the Hall effect sensor communicably coupled to a controller which has a first output coupled to a control signal interface and a second output coupled to the vibration motor, the controller including a processor and a memory coupled to the processor and storing processor-executable instructions, which instructions when executed by the processor cause the processor to perform steps including: receiving, from the Hall effect sensor, first input signals, evaluating the first input signals to determine whether or not the first input signals represent a command for said controlled device by assessing said first input signals for a signal pattern indicative of a plurality of volitional jaw clench actions of the wearer, and if said processor determines that the first input signals represent the command, then decoding the command and transmitting (i) an associated control signal to the control signal interface and (ii) an activation signal to the vibration motor, otherwise not transmitting the control signal and the activation signal and proceeding to evaluate second input signals from the Hall effect sensor in a like manner as the first input signals; and a communication element (34, 36) coupled to the control signal interface and adapted to transmit the control signal from the processor to the controlled device, wherein the communication element is one of: a cable having a plug configured to mate with a jack at the controlled device, and a transmitter adapted for radio frequency communication with a receiver at the controlled device. a vibration motor; a wearable module being supported in a mount of a headset, the headset comprising a frame for wearing over the ears of a wearer, wherein the frame comprises temple pieces, the wearable module including a Hall effect sensor and further including an elongated member and a buckle to slidably mount the wearable module on one of the temple pieces of the frame so as to extend from the temple piece when the frame is worn by the wearer, the wearable module positionable to allow the Hall effect sensor to detect relaxed and clenched conditions of the wearer's masseter muscles when the frame is worn by the wearer, the Hall effect sensor communicably coupled to a controller which has a first output coupled to a control signal interface and a second output coupled to the vibration motor, the controller including a processor and a memory coupled to the processor and storing processor-executable instructions, which instructions when executed by the processor cause the processor to perform steps including: receiving, from the Hall effect sensor, first input signals, evaluating the first input signals to determine whether or not the first input signals represent a command for said controlled device by assessing said first input signals for a signal pattern indicative of a plurality of volitional jaw clench actions of the wearer, and if said processor determines that the first input signals represent the command, then decoding the command and transmitting (i) an associated control signal to the control signal interface and (ii) an activation signal to the vibration motor, otherwise not transmitting the control signal and the activation signal and proceeding to evaluate second input signals from the Hall effect sensor in a like manner as the first input signals; and receiving, from the Hall effect sensor, first input signals, evaluating the first input signals to determine whether or not the first input signals represent a command for said controlled device by assessing said first input signals for a signal pattern indicative of a plurality of volitional jaw clench actions of the wearer, and if said processor determines that the first input signals represent the command, then decoding the command and transmitting (i) an associated control signal to the control signal interface and (ii) an activation signal to the vibration motor, otherwise not transmitting the control signal and the activation signal and proceeding to evaluate second input signals from the Hall effect sensor in a like manner as the first input signals; and a communication element (34, 36) coupled to the control signal interface and adapted to transmit the control signal from the processor to the controlled device, wherein the communication element is one of: a cable having a plug configured to mate with a jack at the controlled device, and a transmitter adapted for radio frequency communication with a receiver at the controlled device.