Every time I analyze a Shopify store in GTmetrix and look at the waterfall, where you can see all the data behavior when loading, I always find a silence.mp3. I have analyzed a dozen Shopify stores and it's always there.
an example: https://cdn.shopify.com/s/files/1/0070/3666/5911/files/silence.mp3?1304
you can check a real store: https://gtmetrix.com/reports/petmania.shop/mb6KTPjP/
There is always a gap (I guess javascript parsing) before this file. Most likely it is always located at the end of the waterfall. But I can't really understand its purpose. Thanks for the help in advance.
After checking and making some R&D it found the file is added in an iframe by the Shopify App called "SuperLemon App"