The vocal characteristics of mean fundamental frequency, jitter, shimmer, harmonics-to-noise ratio, and breathiness were analyzed in 110 (F = 54, M = 56) Arabic-speaking children. The subjects were from. Amman, Jordan, ranging in age from 5 to 20 years. Each subject was tape recorded during the production of the vowels /a/ and /i/. Two second samples of each vowel were analyzed using GW Instrument's Sound Scope software program; Means, standard deviations, and ranges were obtained and summarized for the acoustic measures in each age and gender category. (C) 1997 Elsevier Science Ireland Ltd.