Recordings of jaw acceleration (J x /t 2 ) were obtained in an attempt to provide some information on the nature of the jaw muscle forcing function during speech. The impetus for this approximation was provided by Newton’s second law of motion. The speech wave, intraoral air pressure (P o ), jaw displacement (J x ), and jaw velocity (J x /t) were simultaneously recorded with J x /t 2 to facilitate inferences to net muscle force. Based on the rationale and preliminary data presented here, this interpretation appears to represent a powerful explanatory tool for speech physiology research.