Mouse Calls (AUDIO) University of Wisconsin-Madison Your browser does not support the audio element. Caption Because tiny California mice are usually making noises at a frequency too high for the human ear, this recording of their ultrasonic vocalizations has been slowed to 5 percent of its original speed. It begins with two types of affiliative calls -- the bird chirp of the simple sweep, and the whale-call-like sustained vocalization -- and ends with a monstrous and violent "bark" the researchers compare to an angry dog crossed with a lion's roar. Credit Recording courtesy Josh Pultorak Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.