Described embodiments include a system (74), including a garment (76), configured to cover at least a portion of a body of a subject, one or more sound transmitters (92) coupled to the garment, configured to transmit sound (128) through the body of the subject, and a plurality of sound detectors (22, 96) coupled to the garment. The sound detectors are configured to detect the transmitted sound following passage of the transmitted sound through the body of the subject, to detect body sound (25) emanating from the body of the subject, and to generate a plurality of sound-detector outputs in response to detecting the transmitted sound and the body sound. The system further includes a processor (98), configured to process the sound-detector outputs, and to generate a processor output in response thereto. Other embodiments are also described.