HI is not really necessary. It could simply mean you are growing and quieting down when you do the process. Those imagery sensations are just superfluous anyways and are more like noise that comes up. It is better not to have them. The more calm you are and quiet your mind is the better the process of going from conscious awareness to lucid dreamstate. End result is you have an obe or become lucid. If you can't get to the lucid dream or induce an obe, perhaps you are expecting some kind of HI to come up, not getting it and giving up. don't give up just stay in the state for as long as you can and it will come. depending on your mental state at the time it can take up to half hour or 45 minutes...