Children who look normal until 15-18months and then regress must undergo extensive behavior therapy as early as possible. This will have a big impact on how his behavior modification will propel him/her to speak normally. They key is early diagnosis and early intervention. If you notice regression in the child, with speech delay then intervention must not focus on speech therapy alone, but rather the child must be exposed to extensive behavior modification to be able to acquire speech. It is all interconnected.