Subjects
Healthy participants excluded any otology disease nor vertigo complaints were recruited in our experiments. When compared the three systems at two different clinical center, 9 and 13 participants were recruited, respectively. For the gaze angle experiments, we had 26 participants, 16 of whom we performed the inter-examiner evaluation. The informed consents were obtained from the participants. The experimental procedures in our study were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards.