Excerpt: "A minimal hearing loss can be in only one ear, both ears, or can be the inability to hear high-pitched sounds. Children with this type of hearing loss are able to hear many sounds in their environments, but they often miss soft sounds or sounds of a particular frequency range. Children can have a minimal hearing loss due to a variety of reasons, including genetics, complicated births or deliveries, or exposure to ototoxic drugs. These minimal losses often go undetected because children with such losses are believed to be ignoring or not paying attention since they appear to hear with no apparent difficulty."
"Minimal hearing loss" can be a common cause of school underachievement.
Even Minimal, Undetected Hearing Loss Hurts Academic Performance