Something imitated my husbands voice...

This happened a few days ago.We live 1/4 mile from a state park, along a small side road. If 3 people a day walk/drive past the house it's a lot.

The following post was shared on Reddit by Throwaway83629:

I was sitting in the living room, from the living room I can see the entire street I would notice if someone came to the door but I can't see who's standing in front of the front door from there I have to go to our bedroom window to look. 

Anyway, my husband had left for work about 2 hours before so it was roughly 9:30am. I was having coffee and our son (almost 2) was sitting having his snack. Then I heard someone/something that sounded exactly like my husband(he has a distinct voice and accent) calling "Hello" repeatedly. My son got scared and tried to climb on my lap. I scooped him up and went to the bedroom to see if anyone was at the door, I didn't see anyone but we could still here someone saying hello. It stopped after we went back to the living room. 

Any ideas? I didn't see anyone/anything walking toward the house (with the layout it would be impossible for me not to notice). The voice sounded just like my husband, no one else in the area has his accent and I obviously know his voice but he was 6 miles away at work. After he got back from work we checked for any footprints, etc. there was nothing .