I was driving down the highway in light rain and after signaling to make a lane change the turn indicator noise doubled in pace and stays on unless I signal. Everything else is functional.

That's pretty standard car language for "you have a turn signal bulb burnt out.

Put the signal on, whichever goes faster than usual.

Walk around the car and figure out which one is missing.
If it's hard to tell, put on the hazards and you can tell by what isn't lit up symmetrically.

That is what I thought however all lighting is functioning as it should. To make matters even more confusing it stopped after the car was parked for several hours.

you could have a bad flasher, might been worn out. I couldn't say for sure. since you indicated the bulbs are check out ok, so it has to be a bad hazard flasher or relay as they call it. it's going to be under the dash for sure, but be sure it's definitely no burned out bulb, especially turn the head light on and turn the blinker on because the front signal bulb have two filament on the blinker but the rear will be unlit unless you have the blinker on.