As part of my graduate program, I am required to give presentations to a group of attendees and a program panel about various topics including but not limited to research, involvement, and case studies.
The audience pays attention but rarely ask questions. A survey was released about my effectiveness as a lecturer and nearly 65% of attendees stated my voice was "too authoritative." A common problem was my voice being authoritative and causing the audience to be too timid to ask serious questions related to the topic. Talking in an "enthusiastic" tone (in my own opinion) yielded no results. My voice is very deep and, in order to project well, I tend to speak loudly (no microphones).
What are some tactics to get the attendees engaged and not appear "too authoritative?"
Let me add some details that I find relevant that I missed adding. The survey is handed out as attendees walk in. Between each lecturer there is a 10 minute "intermission" to allow attendees to exit or enter. The attendees are required to hand in surveys as they leave. The uni hosting the lecture combines common themes among the surveys. It is unknown how similarities are determined except to the staff reviewing the surveys. The results are then emailed to the lecturer with good and bad things about the lecture. I am then required to email to my supervisor.