My child has speech delay, he was saying few words around 20months but he he completely stopped talking since about 6months ago. he only makes noise.

Depending on his: other development and his socialization skills, he could have a more profound developmental delay. We can not make diagnoses on this platform, but I would recommend that he be evaluated for hearing loss and autism, by his pediatrician, or if available, a developmental pediatric specialist.

Speak to pediatricia: you should make an appointment to speak to your pediatrician. Have your child's hearing checked and if OK, consider a referral to an autism specialist.