hello.
i have found that, i end up, autonomously, humming as like a frame of reference for physical parts of my body (and the hum can change where it is identifiying depending on circumstance) i have previously enjoyed Mr. Ingrams MCTB and Kasina website, and he's mentioned the ability of mantra's to combine with kasinas. Assuming that a mantra is able to synchroncize with the nimitta of say some kasina practices be it of an external object or internal mental eye lid visuals etc (and that humming can be conisdered a form of mantra), it seems to me this is some phenomnological process that is possible. perhaps the humming is an extension of the possibility of the awareness of breathing and breathe through the air canals etc but more 'obvious'
I do not maintain a formal practice, though I have been exhorted otherwise, and I do want to create a formal practice in my life. to give some personal background, my current practices involve metta/brahmaviharas and sometimes kasina but I do enjoy 'visual input' in my meditation whatever it may be,  but it is not the sole focus of my practice at this time. i have been trying to focus on the more tranquil factors of awakening. I had a brief 'diagnosis' from a wayfaring teacher whom I have both faith and trust in and they stated I was likely in the fear nana and have been for many years, being a 'darknight yogi' without knowing, for some time, as i am sure atleast some have experienced here.
i mention the psychological aspect in the title because it seems that the humming can be both somatically directed in identifying different areas of the body, such as, in the breathe of the body. but also, if one chooses, one can direct ones mind, and use the humming as a facilitation towards moving the mind and body towards certain points of ones interest. Depending on practicioner this can be used wisely or otherwise. So far I have tried to use the Metta or Brahmaviharas to be wise bases for these sort of activities, if they are going to happen anyways (I enjoy intoxicants also magickal/western/tantric practices but just a dabbler for now.) thus bringhs in the psychologoical aspect, it is helpful when used in this way though there are other less skillful ways I have seen in terms of the capability of ones practice to turn; consciously or otherwise.
i know its turned to a ramble, sorry!
i am open to any and all practices, perhaps there are pointers of ways to use this faculty? does anyone else have experience with humming helping? any and all comers are appreciated, thank you
edit: i admit this was more of an intro post to the DHO, hoping to have many more fruitful discussisons here