A question about Audio Previews and where they live

Evening all

A few months ago I noticed PEAK/PEK files starting to appear amongst my video media in my carefully organised file structure

Although I send video previews to a specific location all my scratch files are stored in the same location as the project but generally in specific PP generated folders

When I looked back a few years I can see there was a PP generated "Audio Preview" folder but these are no longer being generated

Is this an "enhancement" or is there a setting somewhere I've missed

Thank you for your help