The best way to avoid infringing on copyright and intellectual property laws is to create your own content from scratch. However, that is not always possible if we are demonstrating models, creating simulations, or gathering information from experts. As educators, we have can "in good faith" use materials under the "Fair Use Determination".
Still, be cognizant of the media you use and cite it when possible.
Audio:
Audacity Resources for Audio:
Lighting:
Filters: