Development of Japanese infant speech database and speaking rate analysis

Utterances of five infants with their parents were recorded every month from their birth until 30 to 60 months old to investigate spoken language development from the viewpoint of acoustic characteristics. Recording time was at least one hour per month. An infant speech database is now being developed from the recordings. Each entry of the database contains a speech file of an utterance and its transcription with some property tags such as speaker, background noise level, and utterance characteristics. A search program with WEB browsing interface was developed for the contents of the database. Using the database, preliminary analysis was conducted on speaking rate. It was observed that infant speaking rate is much slower than parent speaking rate and parent speaking rate is almost equal to the speaking rate of adult conversation.