https://www.smarthomehut.com/how-to-mute-tv-commercials/

Sorry, I have to call "BS" on this theory. The volume of commercials are most certainly amplified, in fact, in the past you could buy a device to mute the volume during commercial breaks. The device would detect increased amplitude and would mute your tv until the amplitude decreased.
How to Automatically Mute TV Commercials - Smarthome Hut