Can also be anxiety....one thing you notice something and you mind get focused on it and there you have it. Ask around almost everybody who turn their head..grind there teeth or whatever here a sound.
You are perhaps just to focused on it and did not notice it before and the more you pay attention to it the louder it will get...just like T. You can talk yourself into an illness if you want. This is just my 2 cents....been there , done that...had the thing you said also....and it was all anxiety and passes when anxiety goes down and your alertlevel of your brain goes down. There are 1000 symptoms of anxiety where you almost think you have an illness or TMJ or what ever. Most of it is anxiety because you body goes in an alert state when you have T and a symptom is that some somatic sounds become more into awareness. Nothing to worry about.....
And if I bite hard on my teeth I also hear a new tone ....... so I just do not bite on my teeth for no reason. Because when you notice this you will also going to notice it when you eating. And perhaps than you go to swallowing and hear you ear make a click sound.
Perhaps if you stand on one hand.....eat a donut and jump rope at the same time you hear crickets in your left ear....perhaps you should stop doing that also than
In other words...do not search for a problem if there isn't any. Most people with T notice more somatic sound ....the least attention you pay to it it will fade in to unconcious again.