FMR1 and fragile X syndrome: Both humans with FXS (Castrén et al., 2003; Schneider et al., 2013; Van der Molen and Van der Molen, 2013; Ethridge et al., 2016) and Fmr1 knockout (KO) mice (Rotschafer and Razak, 2013, 2014; Lovelace et al., 2016; McCullagh et al., 2020) show debilitating auditory hypersensitivity.