The tectorial membrane (TM), which is part of the organ of Corti, is made up of collagens and non-collagenous glycoproteins that envelop both IHCs and OHCs. The longest outer hair cell stereocilia are linked to the TM, and OHCs amplify basilar membrane movement, causing endolymph to flow between the organ of Corti and the TM. This endolymph flow helps IHCs transduce sound signals more efficiently. Pathogenic variations linked to TM-related genes cause hearing loss. The TM contains collagen types II, IX, and XI, which are encoded by COL2A1, COL9A1, COL9A2, COL9A3, COL11A1, and COL11A2, respectively, and variations in these genes cause non-syndromic hearing loss or Stickler syndrome. Glycoproteins unique to the inner ear, encoded by TECTA, OTOA, OTOG, and OTOGL, are also important components of the TM (Goodyear and Richardson J Neurobiol 53:212–227, 2002; Goodyear and Richardson Curr Top Dev Biol 130:217–244, 2018). Pathogenic variants in these genes may lead to hearing loss, i.e., DFNA8/DFNA12 and DFNB21 are reported to be caused by pathogenic variants in TECTA, DFNB22 in OTOA, DFNB18B in OTOG, and DFNB84 in OTOGL, respectively. Recent studies indicate that otogelin, otogelin-like, and stereocilin proteins constitute the “TM-attachment crown and horizontal top connectors,” which link OHC stereocilia to one another and to the TM (Avan et al. Proc Natl Acad Sci USA 116:25948–25957, 2019). This implies that pathogenic variants in genes linked to TM components may result in malformations of the membrane crucial for sound signal amplification. Characteristic features of hearing loss due to these genes are mild-to-moderate sensorineural hearing loss, for which hearing aids are effective. Type IV collagen genes, including COL4A3, COL4A4, and COL4A5, constitute elements of the basement membrane, lateral wall, spiral limbus cells, and Reissner’s membrane of the cochlea, as well as in the basement membranes of the kidney, cornea, lens capsule, and retina in the eyes. Pathogenic variants in the type IV collagen genes result in Alport syndrome, which is defined by progressive kidney failure, hematuria, sensorineural hearing loss, and ocular abnormalities.