The lack of auditory and vestibular phenotypes in mice carrying a heterozygous protein-truncating mutation in Coch,10 and in heterozygous family members of patients with early-onset hearing impairment due to homozygous protein-truncating mutations in COCH,11 illustrate that sufficient functional cochlin proteins can be produced from a single healthy COCH allele. Here, COCH is linked to Hearing impairment.