I also experience such noises, OMJ. I can only speak for myself as to what I think they mean. Here are some of my experiences from my journal:

May 2005, Last night I was awakened at 2:00 am by a quick, one second buzz that seemed to come from my alarm clock. The sound was different to my alarm clock buzz though, and I felt instantly sure that it was set up by my guides. I wondered why they wanted me awake right then, but I ended up falling back to sleep.

May 2005, At 4:00 a.m. I heard electronic beeping noises that came in a particular pattern and lasted about three seconds. I decided not to worry about it and went back to sleep. Frankly, I was feeling too afraid to investigate. A bit later the exact same sounds woke me again. I felt sure the noises were in the physical but was still not at all inclined to investigate. However, I looked at the clock and it was 3:52 a.m. I wondered how this could be when I first awoke at 4:00 a.m., or so I thought. I still do not know why I had time discrepancies, nor do I know what made the noises. I checked my mobile phone in the morning to see if that was the culprit, but there were no new messages that might have made the noise.

June 2005, I was awakened at 6:00 a.m. by a clicking noise that repeated a few seconds later. I knew instantly it was a spiritual nudge...I feel the clicking is intentional and wakes me up at a ripe time for delta brainwaves. It is an opportunity to interact with the spirit realm.

July 2005, I was awakened by a night time clicking again. I felt beings around me giving me messages and willing to help me with my interest of that time (which was a conscious partial spirit exit from body).

September 2005, I was practicing stepping back and forth across the border of sleep and waking consciousness when I heard the familiar repetitive clicking noise in the room (sounds a bit like the click of an automatic cigarette lighter or a ballpoint pen). It startled me. I then saw something on the ceiling. I want to say what that something was, but I do not know how to describe it. Probably because when I sensed it, I was in an altered state that does not directly translate to waking conscious language. It was like a yellow light, but also like a form. I panicked emerging into full stark waking consciousness. I tried to go back to sleep and I heard what sounded like a small chain drop to the floor. Egads! I decided I did not want any more experiences as it was now after 1:00 a.m. and I wanted to sleep. I know there was something or some things in my room that I experienced. Not to say that those things are not always around and I just do not sense them while awake. I do not know.

October 2005, I woke at 3:30 a.m., and as I fell back to sleep, I was alerted to a clicking sound at the side of the bed, which I knew meant someone (spirit) was standing beside me.

October 2005, I have just read Whitely Streiber's book Breakthrough and found many similarities of his that corresponded with mine. One example is when Whitley was awakened in the middle of the night by beeping sounds that he could not find the source for but that were connected with the visitors. This beeping and/or clicking wakes me at times and I have interpreted it as a chance to practice conscious exit or receive a message from my guides.

I have also been wakened in the night by foot steps and other various noises, and all seem to be at ripe times to experience some sort of spiritual thing. My opinion is that it is purposeful.

I have also felt myself "hit", but not hard or hurting, just a spiritual slap to the bottom of my feet and other various places. Often a big boom as if someone did a cannonball dive onto the bed. And my favourite is the little pats I feel along my body sometimes. Lots of little things I could add that would just make this post longer.

One thing I haven't experienced like you, is having my name called. Yet I read this happens to lots of people. Maybe I have too many syllables.

Anything else happen of late regarding these noises? Or any more conjecture?