The CPM gently bends the knee to aide in soft tissue mobility and to prevent scar. tissue from forming. CPMs are designed to help patients increase range of motion of. the operative joint, and by doing so decreasing pain and stiffness of the joint. CPMs. are used often in conjunction with physical therapy.
If your dog is hacking away or constantly making noises that make it sound like he's choking on something, he may have a case of kennel cough, or canine infectious tracheobronchitis. Although kennel cough can sound terrible, most of the time it is not a serious condition, and most dogs will recover without treatment.
Vapors, water or gas tend to amplify sound frequency. Fact. But the dog, depending on it's size, makes an excellent noise barrier. You don't by any chance own the Barrier Terrier breed of dog do you. This would explain the phenom. You probably did not realize it's noise dampening effect, because it is slowly growing up.