The main strategies you can consider either on their own or in combination are:
Ensure key lecture content is available online before the lecture.
Use Panopto to record lectures
Where available, microphones help:
During group discussions, or when responding to audience questions or remarks, repeat what the speaker has said clearly for all to hear. Acoustics in lecture rooms are often poor, and when a forward-facing audience member speaks, few behind them can hear anything. Even in a smaller space, if you are hard of hearing it can be difficult to ascertain exactly who is speaking at any given time, and therefore who to focus on. If the teacher becomes a central conduit for all comments, the student can retain focus.
Owing to the free flowing nature of seminars it is much more difficult to anticipate the content that will be covered or the directions the seminar will go in. Nonetheless, the following recommendations are offered.