Non-acoustic speech sensors have a long history of clinical applications but have only recently been applied to the problem of measuring speech signals in the presence of strong background noise. These sensors typically provide measurements of one or more aspects of the speech production process, such as glottal activity, as a proxy for the actual speech and tend to be highly immune to acoustic noise. In this paper, a new non-acoustic speech sensor based on a tuned electromagnetic resonator collar is proposed. The collar is designed to be worn around the talker's neck and is sensitive to small changes in the dielectric properties of the glottis as well as subglottal and supraglottal systems that result from voiced speech. Unlike the majority of previously developed non-acoustic speech sensors, the proposed sensor does not require skin contact or precise alignment to effectively measure glottal activity. This paper develops the sensor concept and provides analytical, simulated and experimental results that demonstrate the potential of the new speech sensor.