Creating Sound Waves: This site explains how sound is created, provides a quiz on the concepts taught, and gives additional sites for exploration. 

The Effects Objects Have on Sound: This site explains the effects of objects on sound. Topics of discussion include echoes, absorption, and the refraction of sound. Site includes a mini-quiz and additional resources. 

Fear on Physics–Sound: Use this site to teach basic principles of sound. The animation is a little slow but worth the wait for kids. 

Hearing of Sensing Sound: Sound has a direct connection to hearing. This site explores the ear, how we hear, and gives a mini-quiz at the end. 

Physics: Light and Sound: Excellent site for students of all ages to explore many concepts related to light and sound. This is a must use site! 

Sound Waves: This site includes basic information including the characteristics of sound, an interactive quiz and extended sites to connect sound to hearing. 

Speed of Sound: Use this site to help students explore the speed of sound. 

U.S. Berkey Physics Demonstrations-Waves: Black and white wave demonstrations on various sound concepts. This site is more for the teacher than the student.