"Drown out" is a phrasal verb that means to make a sound impossible to hear by making another sound that's louder. The adjective phrase you're looking for is "drawn-out."

You mean "drawn out." "Drawn out" can mean "stretched."

I don't think so because drown out is (of a sound) to be loud enough to drown other sound

The other Dan has it - - you mean DRAWN OUT.

I have never seen or heard drown out being used as an adjective. It is normally a verb. At the political rally, the protesters made so much noise that they were able to drown out the candidate. I use headphones to drown out the noise around me when I ride the bus.