If you can't get professional to record the event, just launch a Google Hangout broadcast on the speaker's computer so the sldie is recorded, add a microphone t

If you can't get professional to record the event, just launch a Google Hangout broadcast on the speaker's computer so the sldie is recorded, add a microphone to him/her under $20 and you good to go. If the speaker is close to the computer just use the built-in microphone.