This document examines the concept of sound in social media and reviews several audio-based social networks including SoundCloud, Audioboo, Bubbly, and Qwips. SoundCloud has grown significantly in recent years and now has around 10 million users after receiving $50 million in funding. It allows users to share a variety of audio content beyond just music. Audioboo focuses on short audio updates but has a smaller user base. Bubbly and Qwips target Asian and North American markets respectively with short voice messages. The document recommends keeping an eye on SoundCloud's continued growth and potential to become an important platform for brands.