Dogs are able to hear noises at such a high frequency that not even human can hear. Trainers use dog whistles to get a dog’s attention. This video contains the sounds of different pitches. I can’t hear past 15000Hz but my boyfriend can’t hear past 7000Hz. http://www.youtube.com/watch?v=fFmiLHaKXhI
I also noticed that my boyfriend speaks very loudly but can never hear me when I speak using my indoor voice. I think that I speak at the necessary decibel level to be heard clearly but I think he does not perceive the loudness of my voice correctly. This isn't a real picture of us, but this is what we look like most of the time and it tends to start a lot of fights in our relationship.