Uncertainty of speech level parameters measured with a contact-sensor-based device and a headworn microphone

This work estimates the uncertainty contributions of speech level parameters measured with a contact-sensor-based device and a head-worn microphone. Four contributions are considered: (1) instrumental uncertainty, related to device calibration; (2) method repeatability and (3) reproducibility, estimated through repeated measurements without and with device repositioning, respectively; (4) source reproducibility, due to the variability of human speech. To ascertain changes in speech production, differences between measures should be at least higher than the expanded uncertainty. In the case of device repositioning, the expanded uncertainty combines contributions (1), (3), and (4). When the device is not repositioned, it combines contributions (2) and (4). (C) 2018 Acoustical Society of America