The prevalence of a traumatic brain injury (TBI) in children and adolescents is around 30% with 70-90% being classified as mild (concussion). Because the brain of a child is still developing, a TBI can have devastating effects and possibly creates lifetime challenges. Sleep seems to play an important role in the post-concussion recovery process. Auditory stimulation during sleep has been shown to reliably boost slow waves, a solid marker for the depth of sleep, and can thus be used to deepen sleep. This study aims to investigate the effects of sleep enhancement via auditory stimulation on recovery after a concussion in children and adolescents in their home. Therefore, half of the patients receive one week of auditory stimulation during deep sleep at their home using a mobile device. The other half follows the same study protocol, but no tones are administered (sham). Cognitive tests as well as symptom questionnaires are used to assess the recovery process. It is hypothesized that the patients in the intervention group will recover better than the ones who haven't received the intervention. Additionally, a group of children and adolescents who never sustained a concussion is included as a control.