These SIRT3-dependent beneficial changes result from SIRT3 deacetylating mitochondrial isocitrate dehydrogenase 2, which increases the levels of nicotinamide adenine dinucleotide phosphate and reduces glutathione, leading to decreased oxidative stress and protection against cochlear degeneration and age-related hearing loss, as is depicted in Figure 2. This evidence concerns the gene SIRT3 and presbycusis.