Probable ion channel required for the normal function of cochlear hair cells (By similarity). Component of the hair cell's mechanotransduction (MET) machinery. Involved in mechanosensitive responses of the hair cells (By similarity). Interacts with TOMT. The interaction of TMC1 and TMC2 with TOMT is required for the transportation of TMC1/2 into the stereocilia of hair cells (PubMed:28504928). Interacts (via N-terminus) with both isoforms CD1 and CD3 of PCDH15 (PubMed:25114259). Localized to the stereocilia of the cochlear hair cells. Inner ear and testis. Expressed at low, constant levels in temporal bone from embryonic day 14 to day 1 after birth. Increases by 8 to 16-fold at day 5, 10 and 20. Belongs to the TMC family.