You are there to learn and so is everyone else. Ask the speaker to say it again in a different way. Bring a small notepad and a pencil. Don't trust your memory. Bring your camera and take photographs.
Film is cheap.
Get close to the display, equipment, or poster. It will make sense and help you remember several months later. Summer and hayracks can be hot. Wear a hat, use some sunscreen, and bring your sunglasses and a water bottle. This information subject to a usage policy .