Listen to Hum & Sough for Relaxation online. Hum & Sough for Relaxation is an Unknown language song and is sung by Restful Sleep Music Collection. Hum & Sough for Relaxation, from the album 220 Tracks: YouTube Videos Background Music – Soundtrack Music for Your Own Video, YouTube Music Videos, YouTube Videos Songs, Download Songs, was released in the year 2015. The duration of the song is 4:15. Download Unknown songs online from JioSaavn.