And you repeat the lie the Washington Post gave 3 Pinocchios 

https://www.google.com/amp/s/www.washingtonpost.com/amphtml/news/fact-checker/wp/2017/03/20/are-firearms-with-a-silencer-quiet/

https://www.google.com/amp/s/www.washingtonpost.com/amphtml/news/volokh-conspiracy/wp/2017/06/19/the-hearing-protection-act-and-silencers/

Unless you don't think you can hear something as loud as a jackhammer that is.   That will 'surely' be 'undetectable'