Evaluation of different antenna types and positions in a stepped frequency continuous-wave radar-based silent speech interface

Joao Vitor Menezes, Pouriya Amini Digehsara, Christoph Wagner, Marco Mütze, Michael Bärhold, Petr Schaffer, Dirk Plettemeier, Peter Birkholz

Silent speech interfaces (SSIs) are subject of growing interest, as they can enable speech communication even in the absence of the acoustic signal. Among sensing techniques used in SSIs, radar sensing has many desirable characteristics, such as non-invasiveness and comfort. Although promising results have been achieved with radar-based SSIs, some of its crucial parameters are yet to be investigated, e.g., the optimal type and position of the antennas. To fill this gap, this study investigated the performance of a radar-based SSI with 3 antenna types attached to 3 positions on the speaker's cheek (9 setups). A corpus of 25 phonemes uttered under co-articulation effects was recorded with the 9 setups by 2 native German speakers and then classified with respect to the phonemes. A linear mixed-effect model was fitted to the resulting recognition rates and likelihood ratio tests showed significance for the effects of antenna type and position. The two monopole-type antennas performed better than the Vivaldi-type antenna (2.7% ± 2.8% and 6.2% ± 3.0% improvement), and the two positions closer to the speaker's lips performed better than the most distant position (decrease of 2.8% ± 0.9%). This provides more solid foundation for the development of this type of SSI.

doi: 10.21437/Interspeech.2022-10431

Cite as: Vitor Menezes, J., Amini Digehsara, P., Wagner, C., Mütze, M., Bärhold, M., Schaffer, P., Plettemeier, D., Birkholz, P. (2022) Evaluation of different antenna types and positions in a stepped frequency continuous-wave radar-based silent speech interface. Proc. Interspeech 2022, 3633-3637, doi: 10.21437/Interspeech.2022-10431

@inproceedings{vitormenezes22_interspeech,
  author={Joao {Vitor Menezes} and Pouriya {Amini Digehsara} and Christoph Wagner and Marco Mütze and Michael Bärhold and Petr Schaffer and Dirk Plettemeier and Peter Birkholz},
  title={{Evaluation of different antenna types and positions in a stepped frequency continuous-wave radar-based silent speech interface}},
  year=2022,
  booktitle={Proc. Interspeech 2022},
  pages={3633--3637},
  doi={10.21437/Interspeech.2022-10431}
}