Relation between feeding and speech
There are similarities in the relation between oral movement patterns in feeding and speech. Some of the processes that will occur in the development of feeding skills are:
1) Tighten the cheeks and pull them inward during sucking.
2) Chewed food from the side to the center of the tongue for swallowing
3) A central grooving of the tongue is observed to support oral stage of the swallow
A similar pattern is required in speech development. The contraction or inward tightening of the cheeks is necessary to direct the airstream forward and prevent lateral air leakage in the production of fricatives ( f,v,zh,sh,z).
During 6-7 month the elevation of the front of the tongue emerge slowly during feeding as the baby shift from early suckle pattern to up-down tongue action of suck. By 9 month the baby shows tongue movements separated from jaw movement resulting in independent tongue tip elevation necessary for ( l,r,t,d).
The refinement of lip contact is also the first feeding movement that reaches a skilled level during nursing and early spoon feeding. Precise lip movements are used to eliminate the loss of liquid during bottle or breast feeding, to remove food from the spoon and to prepare the lower lip for cleaning by teeth. The emergence of consonants produced buy elevating the front of the tongue (t,d,n) occurs for most babies after they have already produced lip sounds(m,b,p). Initially jaw and tongue move together in saying "da-da" or "nah-nah". Sounds require greatest sophistication and finer level of motor control. These require movement patterns are similar to those refined during the chewing process.
These similarities don not prove that feeding skills are pre-requisite to talking. Clinical experience supports the view that when a child experiences difficulty with oral control feeding, there will be similar oral control problems in sound production and speech.