Only a signing parents can fully realize the amount of talking necessary to raise a signing baby. The sheer method is the madness. In order to sign to a baby, a signed word must be put into context, and not just one way, but several different ways. This is necessary in order to help your baby know which word you are talking about. The repetition also helps your baby remember the word and the sign.
It is quite likely the reason why research has found that signing babies are more advanced than non-signing babies. Because signing parents talk so often to their children, and not just in passing, but rather one-on-one, directly, signing babies become part of the family unit very early on. This likely sparks a baby’s brain and starts the language wiring much earlier than the average baby. If you sign, you can probably imagine that most parents will wait until a baby is at least 18 months old, some as late as 2 years before having active conversations with them. This can only serve to delay their vocabulary. The sheer involvement as an equal is what foster early communication in babies.