Almost everyone with tinnitus notices it more at night. The sound itself has not changed — the room has. During the day, traffic, conversation and the fridge all give your auditory system other things to listen to. At night that input drops away, and the contrast makes the ringing leap forward.
There is a second factor. As you wind down, attention turns inward. Without a task, your brain scans for problems, and tinnitus is the most obvious one. So the volume of attention goes up at exactly the moment the volume of the world goes down.
Knowing this lets you reframe the experience. The night-time spike is not your tinnitus getting worse — it is a perceptual illusion you can predict. Add a low, neutral sound to the room, give your attention something gentle to follow, and the spike softens.