Hearing loss causal origins and adapted therapeutic strategies. (A) Hearing loss, defined as mild (loss of 21 to 40 dB HL), moderate (41–70 dB HL loss), severe (71–90 dB HL loss), or profound (>90 dB HL loss), can be due to multiple causes: genetic, noise, and/or age. Whatever the cause, the hearing loss can start any time after birth, with varying degrees of progression and severity. (B) Various therapeutic approaches (gene supplementation, silencing, or gene editing) are being implemented either to protect, prevent and/or repair hearing loss, regenerate or replace inner ear cells.