Is there any signs for being an autistic child silent?

Know what to look fo: The signs of autism are not silent in the sense that once you know what to look for they are pretty apparent. There are many websites describing symptoms.

Pre-school aged: Children with autistic spectrum disorder who have have good pattern recognition & rote memory for learning shapes, colors, numbers & letters & talk about their narrow, repetitive areas of interest like " little professors" may go undiagnosed until social demands unmask non-compliance for following directions for non-preferred activities & lack of interactive, reciprocal pretend play with peers.