Who Said That?

Last night I was washing the dishes and R was with the Dog in the family room which is right next to the kitchen. The Dog was lying on the floor in front of R while he was on his laptop. The only noise that could be heard was the kitchen faucet running. I was nearing the end of dish washing and had just picked up a glass made out of glass to wash, when all of a sudden I hear a voice right behind me. It was a loud gut wrenching voice that sounded like an "UH!"
I thought R had snuck up behind me and was trying to scare me. At the same time I almost dropped the glass glass in the sink! Immediately I turned around and said, "what was that?" And guess what? No one was there! I assumed R quickly dashed out of the room, so I shout it louder at him, "what was that?!?!" Still no answer. So I walked into the family room to find the Dog and R in there and I shouted again, "What the hell was that?!?!"
Finally R answers me and said, "I thought that was you saying something Even the Dog heard it and looked up from her nap towards the kitchen!"
Me: "No Way! I didn't say anything! It sounded like you snuck up behind me and yelled something to scare me!"
R: "No, it wasn't me! I thought you said something because it sounded like it was coming from where you were standing in front of the sink!"
Me: "I was at the sink washing dishes and all of a sudden I hear that voice say something right behind me rather loudly so I thought it was you!"
R: "No, I just said it wasn't me! And if it wasn't you, who said that?"
Me: "Are you sure it wasn't you?"
R: "No, I'm not kidding, it wasn't me! And the Dog heard it too!"
Me: "Oh sh*t! Then who said that?"
R: "That's what I want to know! What did it sound like to you? Because to me it was definitely a voice."
Me: "Yeah, it was definitely a voice! It sounded like a very loud guttural "UH!" AND it was right behind me!"
R: "It sounded like that to me too. Well, that's something...that all three of us heard it at the same time."
Me: "Yeah, but...who or what said it?"
At that moment I got chills and started shaking a bit. And it takes a lot to creep me out!
I finished the dishes but I kept looking over my shoulder til I was done.
R says it was like someone was being mischievous with me.
We still don't know who or what that voice was but later on last night we did see some shadow people. I saw one in the kitchen/dining room area and R saw one by the front door.
Last night was a very weird night to say the least.