Hello,
Well I don't mean to sound like a skeptic or anything, but do you have older women neighbors who happen to speak a foreign language?
I know my Assyrian neighbors hang out in their back yard at night all the time and I can hear them talking lol.
But anyways, has it happened to you more than once? Did it stop when you went in the house? What was the "atmosphere" like i guess you could say, like did you get a weird feeling when you heard the voice?
Sorry for the questions, I'm just curious and want to figure it out because most people who hear voices in foreign language usually have something associated with an evil kind of entity, but I don't want to freak you out! I'm not saying it's like that, it's just one of those theories. I would really like it if you provided more details too =)
Peace!