Crossbow decibel level questions

Hey fellas,

Has anyone ever done any sound ratings in decibels of various Crossbows?

i’m actually inquiring on behalf of a friend who has a death stalker.

He was contemplating buying one of these
Benjamin Bulldog .357 air rifles. He was under the impression that they were quieter than his scorpyd death stalker.
But my research found out that they are somewhere around 90 dB to 100 dB.

Have they done any sound ratings on either the death stalker or other Crossbows? If so what are the various decibel levels?

thanks for any helpful advice.