Wearable skin vibration or silent gesture detector

A device, comprising:

• a frame configured to be worn by a user;
• a self-mixing interferometry sensor mounted to the frame and configured to emit a beam of light toward a location on a skin portion of the user;
• and
• an interpreter configured to:
• receive a self-mixing interferometry signal from the self-mixing interferometry sensor;
• detect a first skin vibration information in the self-mixing interferometry signal;
• detect a second skin vibration information in the self-mixing interferometry signal, wherein the second skin vibration information includes vibration information different from the first skin vibration information;
• and
• transmit one or more signals responsive to a detection of the second skin vibration information in the self-mixing interferometry signal, the one or more signals indicating a movement unrelated to a voiced command.

A device, comprising:

• a frame configured to be worn by a user;
• a self-mixing interferometry sensor mounted to the frame and configured to emit a beam of light toward skin of the user;
• and
• an audio conditioning circuit configured to:
• receive a self-mixing interferometry signal from the self-mixing interferometry sensor;
• detect skin vibration information in the self-mixing interferometry signal;
• and
• determine time intervals of non-speech of the user based at least in part on a detection of the skin vibration information.