The purpose of PECS is to establish a functional picture communication system within a social context. The premise is that pointing to a picture isn’t communication unless the child engages someone’s attention.
Teaching a child to verbally produce speech is NOT a goal of PECS. The philosophy of the training program is that an individual must understand the purpose for communication before engaging in actual speech production. Verbal utterances aren’t encouraged or responded to in the program; only non-verbal exchanges are rewarded.