My partner and I are teaching our 14 month old daughter Auslan so she can communicate when older with her grandmother who is deaf, so far she knows how to sign about 12 signs and we always talk when we sign, could teaching her sign language slow down her speech?
Research has highlighted that it actually accelerates the speech process. Part of the process of introducing baby sign language is to sign and say the word. It is very important to say the word as you are encouraging speech. For more information on the research of baby sign language you can visit the website here.