3 musical balls with different sounds to stimulate the baby's sense of hearing! Made of 100% natural rubber, these 3 musical balls are light and easy to handle! 3 actions are necessary to activate 3 different sounds: By lightly squeezing the green ball, the baby hears the soft sound of crumpled paper By shaking the white ball, a bell tinkles By pressing briefly on the yellow ball, Sophie's famous " poet " sounded! Baby develops his auditory sense and discovers and understands the notion of cause and effect.