A wearable device for measuring a tympanic temperature, the device comprising: an ear insert formed to extend along an ear canal of an ear in use, the ear insert comprising: a blocking member provided at a proximal portion of the ear insert, the blocking member configured to substantially block the ear canal in use; an ear canal extending member extending in a distal direction from the blocking member into the ear canal in use; a thermopile module provided at a distal end of the ear canal extending member and supporting an infrared thermopile at a distal end face thereof; one or more centralising portions, together configured to substantially centralise the infrared thermopile within the ear canal, the ear canal extending member and the one or more centralising portions being configured to locate the infrared thermopile in the ear canal for measuring a tympanic temperature in use; and an audio conduction channel at least partly defined within the ear canal extending member, the audio conduction channel configured as a waveguide to conduct sound through the blocking member to a distal portion of the ear insert, wherein an output of the audio conduction channel is defined in the distal portion of the ear insert, in a proximal direction from the infrared thermopile, and is arranged to open in the ear canal, in use. an ear insert formed to extend along an ear canal of an ear in use, the ear insert comprising: a blocking member provided at a proximal portion of the ear insert, the blocking member configured to substantially block the ear canal in use; an ear canal extending member extending in a distal direction from the blocking member into the ear canal in use; a thermopile module provided at a distal end of the ear canal extending member and supporting an infrared thermopile at a distal end face thereof; one or more centralising portions, together configured to substantially centralise the infrared thermopile within the ear canal, the ear canal extending member and the one or more centralising portions being configured to locate the infrared thermopile in the ear canal for measuring a tympanic temperature in use; and an audio conduction channel at least partly defined within the ear canal extending member, the audio conduction channel configured as a waveguide to conduct sound through the blocking member to a distal portion of the ear insert, a blocking member provided at a proximal portion of the ear insert, the blocking member configured to substantially block the ear canal in use; an ear canal extending member extending in a distal direction from the blocking member into the ear canal in use; a thermopile module provided at a distal end of the ear canal extending member and supporting an infrared thermopile at a distal end face thereof; one or more centralising portions, together configured to substantially centralise the infrared thermopile within the ear canal, the ear canal extending member and the one or more centralising portions being configured to locate the infrared thermopile in the ear canal for measuring a tympanic temperature in use; and an audio conduction channel at least partly defined within the ear canal extending member, the audio conduction channel configured as a waveguide to conduct sound through the blocking member to a distal portion of the ear insert, wherein an output of the audio conduction channel is defined in the distal portion of the ear insert, in a proximal direction from the infrared thermopile, and is arranged to open in the ear canal, in use.