Otoferlin deficiency leads to impaired cochlear synaptic transmission and is associated with progressive hearing loss in adults. Didhiti and Ying wondered if loss of Otoferlin also had effects on cortical development. They found that spontaneous and sound-driven cortical activity in the first two postnatal weeks was impaired in Otoferlin knockout mice. Moreover, they found that in these mice subplate neurons received exuberant connections from within the cortex. Thus, otoferlin deficiency has a powerful influence on cortical connections and spontaneous activity in early development even before complete deafness. Therefore, peripheral activity has the potential to sculpt cortical structures from the earliest ages, even before hearing impairment is diagnosed. Read the full paper here in Cerebral Cortex.