Recording speech articulation in dialogue: Evaluating a synchronized double electromagnetic articulography setup

We demonstrate the workability of an experimental facility that is geared towards the acquisition of articulatory data from a variety of speech styles common in language use, by means of two synchronized Electromagnetic Articulography (EMA) devices. This approach synthesizes the advantages of real dialogue settings for speech research with detailed description of the physiological reality of speech production. We describe the facility's method for acquiring synchronized audio streams of two speakers and the system that enables communication between control room technicians, experimenters and participants. Further, we demonstrate the feasibility of the approach by evaluating problems inherent to this specic setup: The first problem is the accuracy of temporal synchronization of the two EMA machines, the second the severity of electromagnetic interference between the two machines. Our results suggest that the synchronization method used yields an accuracy of approximately 1 ms. Electromagnetic interference was derived from the complex-valued signal amplitudes. This dependent variable was analyzed as a function of the recording status - i.e. on/off - of the interfering machine's transmitters. The intermachine distance was varied between 1 m and 8.5 m. Results suggests that a distance of approximately 6.5 m is appropriate to achieve a data quality comparable to single speaker recordings.