In this video I measure the sound level of the DeWalt DW735 planer with a Byrd Shelix helical head. I used the Decibel 10th app on an iPhone 5s. The phone was 3ft away from the side of the planer with the microphone pointing towards the planer.
DEWALT Thickness Planer, Two Speed, 13-Inch (DW735) (Amazon Affiliate)
US: https://amzn.to/397NKYf
CA: https://amzn.to/2YZvQoR