The two opposing words, happy and sad, have been chosen to demonstrate the transition from one feeling to another.
*Audio credits: Boring Sound - https://www.youtube.com/watch?v=CIuSMI2-l58, Haha Sound - https://www.youtube.com/watch?v=z1bMply_7tU, Crying Sound - https://www.youtube.com/watch?v=PS34VB-hidg, Magic Sound - https://www.youtube.com/watch?v=2MhHiKajn8o, Lightening Sound - https://www.youtube.com/watch?v=ki4a4d7wJRQ
