Although I live alone, I really live "alone" in that I share a wall with my neighbors. The wall is concrete which is nice except that it stops about a foot before it meets the ceiling. Thus... although I am the only one in MY house, I can HEAR my neighbors. I hear them talk. I hear them fart. I hear their TV/alarmclock at 5 am. I hear baby coo. I hear dad play with baby. I hear mom sing. I hear baby cough and cry. I hear mom and dad yelling and hitting each other. I hear things being thrown and breaking. I hear mom crying. I hear their lives.
From outside the house: I hear trucks going by. I hear thunder. I hear evangelical preaching and blaring music. I hear the fan running in the house next door. I hear dogs bark. I hear roosters crow. I hear dogs bark and roosters crow all night long. I hear crickets and birds and frogs and geckos sing. I hear mice and rats scampering. I hear rain on my tin roof so loud it drowns out everything else.