Purpose: Conventional resource-intensive methods for child phonetic development studies are often impractical for sampling and analyzing child vocalizations in sufficient quantity. The purpose of this study was to provide new information on early language development by an automated analysis of child phonetic production using naturalistic recordings. The new approach was evaluated relative to conventional manual transcription methods. Its effectiveness was demonstrated by a case study with 106 children with typical development (TD) ages 8–48 months, 71 children with Autism Spectrum Disorder (ASD) ages 16–48 months, and 49 children with language delay (LD) not related to ASD ages 10–44 months.