[Harp-L] throat vibrato

[Jimmy D <jimmyd1147@xxxxxxxxxxx>]

I have been playing harp for over 10 years.My throat vibrato is not great. I have practiced the throat exercises some. I decided today i am going to  practice these throat exercises daily until i get it.For those of you with decent vibrato .Did it take a lot of practice?  Tongue blocking came easy for me.Is it like that with vibrato. Does it come naturally for some? Can it be learned through intense practice ?
thanks 
jimmy