Ear-worn devices for physiological monitoring

An ear-worn device, comprising:

• a speaker, an optical emitter, an optical detector, and a processor;
• a housing configured to be positioned within an ear of a subject, wherein the housing encloses the speaker, optical emitter, optical detector, and processor, wherein the housing comprises at least one window that exposes the optical emitter and optical detector to the ear of the subject, and wherein the housing comprises at least one aperture through which sound from the speaker can pass;
• light transmissive material between the optical emitter and the at least one window that is configured to deliver light emitted from the optical emitter to an ear region of the subject at one or more predetermined locations;
• light transmissive material between the optical detector and the at least one window that is configured to collect light external to the housing and deliver the collected light to the optical detector;
• and
• at least one lens external to the at least one window, wherein the at least one lens focuses light emitted by the optical emitter and/or collects light reflected from the ear region;
• wherein the processor is configured to receive and process signals produced by the optical detector.