A heart rate sensing system (300) includes a light source (112, 310, 1008, 1110) a light detector (114, 1010, 1112) and a pressure sensor (116, 1012, 1114) held by a compressible comformable resilient pad (110, 1006, 1108) against a wearers body (202). A signal from the pressure sensor is used to alter the amplitude of a signal detected by the light source in order to reduce motion artifacts. The system can be incorporated into an article, such as an ear cuff (100), an audio headset (1000) or a set of headphones (1100), that is suitable for use by an active user.