Pore-forming subunit of the mechanotransducer (MET) non- selective cation channel complex located at the tips of stereocilia of cochlear hair cells and that mediates sensory transduction in the auditory system (By similarity). The MET complex is composed of two dimeric pore-forming ion-conducting transmembrane TMC (TMC1 or TMC2) subunits, and aided by several auxiliary proteins including LHFPL5, TMIE, CIB2/3 and TOMT, and the tip-link PCDH15 (By similarity). MET channel is activated by tension in the tip-link extending from the side wall of one stereocilium to the tip of the adjacent shorter stereocilium, where the channel is located (By similarity). TMC1 MET channel is highly permeable to calcium and likely transports monovalent cations (By similarity). Also involved in vestibular hair cells transduction current (By similarity). . This is the function of TMC1 (transmembrane channel like 1, Ensembl gene identifier ENSG00000165091).