Until getting him, I had forgotten how much I tend to rely on dogs when they are present for certain sounds. When there is a dog in the vicinity and I hear a strange sound, I look at the dog first. Their reaction will tell me a lot about the sound that I wouldn't otherwise realize without investigating it myself.
His excited movements let me know if someone is at the door. Conversely, he also lets me know if a sound is no big deal. I was playing a video game the other day and kept hearing something odd. I couldn't tell if it was from the game, from the house, or outside in the neighborhood. I paused the game, and looked at Raiden. He hadn't reacted much to the sound at all, which I took to be a clue it was not very close by or important. It turned out to be a neighbor using an oddly pitched power tool in their backyard.
Raiden may not be a hearing dog, but having him around, I have realized how much dogs can contribute to my awareness of the world. (I love cats, too... but let's face it, they ignore a lot more things than dogs do.) I think I will start some training for him to let me know when my phone rings!