I have all kinds of noises in my head (hissing, buzzing, beeping, a kind of cycling on the left side) plus pulsatile tinnitus when I lay down. I observed a lot, read a lot, and tried a lot of things to try and help this. Here is one exercise that helps:
youtube.com/watch?v=WuCzmHN...
You can follow this doctor so that you get the full range of his exercises, but I would go very slowly in the beginning.
From the posts I've read here and what my practitioners have said, I understand that sometimes the meninges gets out of place after meningitis. (One practitioner said that after it expands from the inflammation, it may contract later.) Also, if you already had some neck problems (tight muscles, cervical vertebrae issues), this will make recovery harder. I imagine that gently increasing the blood flow helps.
I've said this elsewhere, but I have also found that the following helps (I would not do this if you are recently sick): applying moist, warm heat, especially at night, to my neck, side of my head and shoulders (I use a washcloth, a hot water bottle with a damp towel or the shower--I would not use a heating pad); other neck exercises; massaging my scalp (but only the scalp, I avoid that tender spot just below the cranium in the center, where the spinal cord is); doing modified "rabbit pose" (I just put my forehead on the yoga mat; I do not push my chin to my chest); gentle stretching and walking; doing slow neck rolls while crossing my legs and stretching my hands straight to the floor (this gives you a greater stretch than regular neck rolls); putting my neck down and holding the weight of my hands on the back of my head to give it some gentle pressure; avoiding loud noises (especially amplified sound); using ear plugs; chiropractic; osteopathic-like work; cranio-sacral work. Taking magnesium. Getting a good night's sleep. Taking herbs to help me sleep.
Don't forget to breathe slowly while you do these things (and I wouldn't do all of them to start). I recommend incorporating one change per week to see if it gives results.
I'd be curious to see if this helps anyone.