From a study conducted by D.L. Wells, L. Graham, and P.G. Hepper:
Conducted in an animal shelter in the United Kingdom and published in the journal Animal Welfare (Vol. 11, No. 4), the study investigated the behavior of dogs in response to five different types of aural stimuli: heavy metal, pop music, human conversation, classical music, and no music (the latter served as the control group). Knowing that research has already established the influence of music on human psychology, scientists D.L. Wells, L. Graham, and P.G. Hepper were interested in determining whether certain sounds had the potential to relieve the stress of dogs in a shelter setting.Fifty male and female sterilized dogs were used as subjects. Most of the dogs were mixed-breeds—thus preventing any valid analysis of whether Chihuahuas are more partial to scampering Mozart and Dobermans to thundering Wagner—and all were housed singly. Researchers placed a CD player/radio at the center of the kennels and monitored decibel levels to ensure even distribution of sound to all the dogs. The researchers then exposed the dogs to each condition (no music, pop, heavy metal, conversation, and classical) for four hours over the course of five separate days. To control for possible interference from other stimuli like kennel cleaning and feeding, the sound was always provided at the same time of day, and music was played in different order each time to ensure that the order played had no effect.
Each dog was observed every ten minutes during the four hours of stimulation, and at each observation researchers recorded where each dog was in his kennel, what he was doing (standing, sitting, resting, sleeping, or moving), and whether he was vocalizing (through barking or other noises).
Researchers found that the dogs did not tend to seek out the source of any of the auditory stimuli conditions, and did not seem to care whether they were closer or farther away from the radio. However, the type of sound was significantly related to both activity and vocalization of the dogs. The dogs spent much more time resting when classical music was being played [emphasis added] than they did during any of the other conditions; those results were the same for the control group, to whom no stimuli were provided. The dogs also vocalized far less during the classical music than during the other conditions; the heavy metal music provoked more barking than other sounds. [emphasis added]
“Neither pop music nor human conversation had any apparent effect on the dogs’ behaviour,” the researchers wrote. “It may simply be the case that dogs are more accustomed to these types of auditory stimulation than others. Shelter staff … regularly listen to radio … involving a mixture of human conversation and pop music whilst undertaking their husbandry duties. Very few, however, listen to classical or heavy metal music within this particular working environment.”
Playing classical music in shelters may create an environment less stressful for dogs, the researchers concluded. It also may have an indirect benefit, since “visitors are often deterred from adopting a dog from a rescue shelter because they consider the animal’s environment off-putting.” Calmer dogs who bark less and the presence of classical music may get visitors to spend more time looking at the dogs and may result in an increased number of adoptions, the researchers wrote.
It would be very interesting to see this experiment repeated with other types of animals. Animal research, in both psychology and medicine, has long been a precursor to human research. We’ve already seen experiments done with fish, rats, mice, and birds; although it’s tempting to generalize these studies to our children, we should be wary. However, it’s clear that animals do have decided preferences in music, and this suggests research avenues to further understand how classical music benefits both our animal and human family members. I know my own animals, who had the run of the house and yard, always came to hear me sing!