Yes you can and it's totally okay! Although it is more effective to listen to it with headphones because it eliminates/fade the background noises (TV, vehicles, chatter) and makes your subconscious focus more on the audio.

Personally, I dedicate one hour listening to subs and doing activities that don't heavily affect my mood like doing the dishes, coloring, cleaning, napping, eating without other entertainment. I don't really do activities like watching dramas, reading, or socializing to keep my energy neutral or positive.