Listen Up SmartLab Author:Paul Beck For undercover operations or pure fun, the voice changer is the ultimate combination of silly and science! Includes everything kids need to build a working voice changer. Kids can choose to have a scary, squeaky, robotic, or booming voice. Read all about it! Learn about voices, vibration, and how sound is created and digitally altered. Ages 8 an... more »d up. Product Dimensions: 8.5 x 11 x 3« less