How do you knwo when speech emerged? Speech would come long before written language.
Mechanically, the hyoid bone in your throat is the bone that gives us the ability to speak. This bone is present in many mammals, including all the great apes, but in humans it is lower in the throat, giving us more room for more tongue movement. This bone has been found in much the same place in the skeletons of neanderthals, making it highly likely that they had some form of speech, and meaning that the ability to speak is far older than a mere 6,000 years.