Conducted spectrum analysis of standard and vociferous cries from infants with Wessel's colic, non-Wessel's colic, and comparison infants. Vociferous cries had longer duration, higher fundamental frequency, and greater percentage of dysphonation than standard cries. After feedings, problematic criers had greater percentage of dysphonation in vociferous cries than comparison infants, and Wessel's colic infants had higher dominant frequencies than others. (Author/KB)