By default when you visit a page with a Poodll audio or video recorder with Safari browser (Mac OS) you will see a permissions request dialog, like this:

You should click "Allow.

Telling Safari to remember your choice

You can tell Safari to remember your choice for your school's website. And it will stop asking you each time. To do this visit the "Safari -> Preferences" menu.

From there choose "Microphone" from the options on the left hand side. The current website and a drop down list will appear on the right hand side. Choose "Allow". Also select  "Camera" on the left menu and choose "Allow"