Open and direct feedback from the students is important for the quality of the educational process. Adapting the curricula using the right correlation with the requirements of society but also with the actual knowledge level of students is generally accepted and promoted but not easily done. In this paper are presented the results of the students' evaluation of the "Signal Processing" course over a period of five years, the last of which was impacted by the transition to the full online teaching. Comparative results for this year are presented and possible explanations for the differences are investigated.