HVI-Certified Ratings Explained, Part 2: Sones (Sound) – HVI-Certified products are evaluated for certain performance parameters including airflow, sound, and energy. In this video, we explain the meaning of the HVI-Certified rating value “Sones” and what it means in regards to sound. A complete list of HVI-Certified product categories and their corresponding performance parameters can be found in the HVI-Certified Ratings Programs section.