Dogs have sense of humor, college reports

Lake Tahoe, Nev. - Laughter is the best medicine - even dogs willtell you that, report researchers at Sierra Nevada College.

Students and faculty at the college say research indicates dogs laughwhen participating in special occasions with their human companions.

"To the untrained human ear, it sounds like a pant, a huh, huh,"says Patricia Simonet, animal behavior professor.

"We called the vocalization a laugh, because this particular soundwas only ever observed during play or friendly greetings. We never heardor recorded this sound during agonistic encounters. It appears as thoughthis particular vocalization is exclusive to play or friendly encounters,"she explains.

Simonet backs up the findings with recordings of the frequency analysisof amused dogs, with frequency analysis, which reveals a large range ofsounds dogs produce. The research, which tested 15 dogs in a control groupand 15 dogs in the experimental condition, showed 15 puppies that respondedto hearing a recording of a dog "laugh" by tossing chew toys andromping around.

"Furthermore, when we tested the different vocalizations that wehad recorded during play, using a playback experiment, the growls, whines,and barks alone did not elicit play behaviors. However, the 'laugh' or breathyexhalation alone did elicit play behaviors," Simonet says.

The research is far from complete, she adds.

"The study suggests that domestic dogs have a wide and varied repertoireof vocalizations beyond barking, howling, whining, and growling. The breathyexhalation that we call a laugh is very distinct from a pant and yet humanshave considered the dog to be panting. Dogs respond to the laugh, even ahuman imitation of a dog laugh, by engaging in play. We have even recordeddogs producing this sound when engaged in solitary play.

"We are interested in investigating dog vocalizations in the ultra-sonicrange to see if we are missing anything else."