Sound is usually studied in preschool as the hearing part of a science unit about the five senses. Give them plenty of opportunities to ask questions, explore and investigate new materials as they learn about sounds in the world around them.
Sound, along with the five senses, is a good unit to teach early in the school year. Later in the year preschool students can use their five senses to explore and observe other science topics such as properties of matter, plants and animals.
You can introduce your students to sound with bells, musical instruments and sounds they hear on a listening walk around the school. You can also let them experiment with vibrations and water's effect on sound.
Teach your preschool students about some famous people who are known for their work with sound. Composers such as Mozart or Beethoven or scientists such as Alexander Graham Bell are good choices.
Reading books with your students is a good way to add to their knowledge and experiences with the topic of sound. Your students will enjoy learning about sound with books like "Oscar and the Bat" by Geoff Waring, "Sounds All Around" by Wendy Pfeffer and "Zin! Zin! Zin! A Violin" by Lloyd Moss.