Fig. 2From: Hearing impairment in MELAS: new prospective in clinical use of microRNA, a systematic reviewTwo methods are used for investigating the hearing pathways. Cochlear function is investigated by OTOAE/TEOAE/DPOAE (which can identify the hair cells damage). The retro-cochlear portion is investigated by ABR. The table on the left shows the area that generates the specific wave; the image shows the area and the waveBack to article page