My wife listens to podcasts or the radio to go to sleep. I can't go to sleep with any voices in the room - I just listen to the words and can't get to sleep at all.
The absolute best gadget over 20 years of trying out ways to let my wife listen while I hear nothing has been
SleepPhones. Readily available, e.g. Amazon. A soft fabric headband containing flat speakers. The speakers are removable so that the headband can be washed. The speakers sit right on the ear, but are so flat they are comfortable even if you sleep on your side with your ear on the pillow. Worth every penny.
[EDIT: One more case of I should read to the end before commenting! Just take it as another vote for sleepphones.]