A:AnswerHi - Thank you for your interest in this beautiful GE Profile Designer Hood. The sound level is rated in sones at High Speed and at Working Speed which is the lowest speed at which you can reach 100 CFM. The sones level on High is 7.5 and 0.04 at Working Speed. Working speed is a testing level required by HVI (Home Venting Institute) to enable you, our customer to be able to compare the sound level of vent hoods more easily. We do hope you choose GE for your home. Vikki@GEA