WE TEND to speak more slowly and carefully when we鈥檙e trying to be understood. Now it seems you don鈥檛 even need to slow down. Speaking more deliberately even at full speed is much easier to understand than normal speech (Journal of the Acoustical Society of America, vol 112, p 2165).
Jean Krause and Louis Braida from MIT carried out the research, and say their next goal is to find specific characteristics of 鈥渃lear speech鈥� that distinguish it from normal speech. A device that could convert one into the other could be used in hearing aids or loudspeakers to make speech clearer as well as louder, they say.