A common misconception is that speech is language and language is speech. Recently, with the studies of deaf babies, Dr. Petitto has said, "We decoupled language from speech. We've torn them apart" (New York Times, 2002). Over many years, researchers have studied hearing babies and recognize their attempts to speak with what they call "baby talk." Hearing babies, with hearing parents, will say things such as "dadada" when first learning to construct words. New research has shown that deaf babies, with deaf parents, have hand movements that are the equivalent as "baby talk." "Deaf babies of deaf parents babble with their hands in the same rhythmic, repetitive fashion as hearing infants babble with their voices The motions seem to be the deaf babies" way to master the language [sign language]"(NYT, 2002). It has also been found that deaf babies and hearing babies progress at the same rate when learning the "speak" their language. "The deaf babies, who presumably watch their parents use sign language at home, start their manual babbles before they are 10 months old, the same age hearing children begin stringing together sounds into wordlike units"(NYT, 2002). Everyday new research is being conducted. These studies are helping to expand researchers knowledge of language development and are leading to the questioning old theories such as, "the maturation of the vocal cords affects language development in infants" and moving onto new theories that include ideas such as "language is a progress from one stage to another," similar to Piaget's Stages of Cognitive Development or Erickson's Stages of Psychosocial Development. (NYT, 2002).