Working on your throat chakra, clairaudience, clairvoyance points and your third eye should give you positive manifestations. For most people usually they hear buzzing noises at first, a set of a few words or just impressed thoughts. With time and work on your chakras this should get easier. Some people are natural mediums and can communicate and invoke clearly before they even dedicate or know what they're doing. Some people can be born with damaged throat chakras and have severe issues with astral senses in general when in an awake state or a trance. Good news is even if you have a problem like that, astral projection can circumvent the need to be able to physically invoke a god. For beginners the best method is learning to trust your intuition, emotions, thoughts and possible correspondences that happen after workings. I wouldn't focus on obtaining results like being able to talk, see or hear a god. The best thing to do is to just do consistent and general workings for advancing yourself. Raising your energies and keeping them raised will increase your tolerance for bioelectricity, which will in turn start healing your aura and chakras which also leads to some of your abilities developing. If you focus on their sigil or enn you can be sure that the demon you're working with can hear you.