Word Request – Verb for Listening Stealthily

My first thought was the word goosebumps (which often refers to literal goosebumps, but can be used figuratively as well, as in, "That music gives me goosebumps."). Then I saw an article that said:

Why Does Great Music Give You the Chills?

Have you ever been listening to a great piece of music and felt a chill run up your spine? Or goosebumps tickle your arms and shoulders?

The experience is called frisson (pronounced free-sawn), a French term meaning “aesthetic chills,” and it feels like waves of pleasure running all over your skin.

Listening to emotionally moving music is the most common trigger of frisson, but some feel it while looking at beautiful artwork, watching a particularly moving scene in a movie, or having physical contact with another person.

I don't think the word is all that well-known, but it might be exactly what you are experiencing. The word chills (used in the article's headline) might be a more well-recognized substitute.

I'm not aware of any single word that isn't context-specific but, like Ronald Sole in his comment, I would be more likely to use "aloud" instead of "out loud" (both are acceptable).