If you are looking for long-duration relaxation or sleep music by Sevda Şengüler, you may be thinking of one of these "1 Saat" (1 Hour) versions from platforms like Apple Music or YouTube :
A long-play version of the "Smiling Baby" track. Green Noise vs. Sevda Şengüler
A continuous loop of one of her most famous lullabies.
The term in your query might refer to Green Noise , which is a type of background sound similar to white noise but focused on nature-like, mid-range frequencies. These "1 Hour Green Noise" tracks are frequently used alongside lullabies for deep sleep and meditation. Summary of Notable Works
An hour-long "Angel Baby" lullaby.
