Does your dog love to squeak, squeak, squeak and you could use a break from all the noise? Then these happy toys from Hear Doggy might be the perfect compromise. Dogs can hear sounds at a higher frequency (0 to 45KHz) than humans (0 to 20 KHz). Tuned to an ultrasonic range in the 24-28 KHz frequency, each Hear Doggy squeaker is out of human hearing range, but still fun for your four-legged friend. These toys are very tough as well!