The patient group consisted of 20 depressed outpatients who were attending a university-affiliated research clinic, and the matched-control group consisted of 20 healthy adults who were recruited from the New York metropolitan area. The patients and controls were screened to exclude those with any of the following: serious suicide risk, substance abuse disorders (including alcohol abuse) within the last 6 months, psychotic disorders, antisocial personality disorder, seizure disorder, organic mental disorder, history of head trauma, or other neurological disorder. A standard audiogram was used to exclude those having a hearing loss greater than 30 dB in either ear at 500, 1000 or 2000 Hz or if they had an ear difference greater than 10 dB. All participants gave written informed consent before participating in the study and were paid $15 per hour.
