Clicking sensation in my skull

Hi Bonnie,
I’m wondering if you might be able to help me make sense of something that been ongoing for a few years now. When I’m healing or clearing or meditating (some type of spiritual work) I notice a clicking sound in my skull. It usually is concentrated in one location like for example near my left ear, but when I am engaged in my spiritual practice it starts to give off periodic clicking noises. This can be quite distracting as I don’t know what this is or where it’s come from? I think it’s been with me for around 4+ years now. Once I’m done with my practice it’s gone. When I feel myself zoned in again, it’s back. What is this? I’ve noticed it to be in a few different spot at times, but currently, I have been noticing it in the area of my left ear.