There was a time when I was actively exploring the activity of spirits in my environment, and at that time I found myself aware of more spirits, but it was just that I was organizing information differently--it was useful for some things, not useful for others. You are more concerned with spirits of the dead, and I've had no experience there, except for one dream. My experience of people dying is that much of what they were gets redistributed to the living, and their stream of consciousness seems still to hover about the body or the place of death for a bit. It seems to me that it would be unkind to seek out the dead shortly after they die, because you could distract or disturb them at a time when what consciousness they have should be attentive and at peace. So to answer one of your questions, I wouldn't try to speak with the dead.