Specific investigations of pediatric hearing loss are based on the history, physical examination, and age of the patient. The radiographic investigation of choice is high-resolution CT of the temporal bone. Patients with a dilated vestibular aqueduct need to be investigated further for Pendred syndrome. Screening for mutations in connexin 26 has become increasingly available in many centers and should be performed in all cases of nonsyndromic hearing loss. It is important to understand the implications and pitfalls of genetic testing. Genetic counseling is necessary.