Michelle McKnight does not even notice the noise anymore, though it can be clearly heard, even over a phone call. It is the sound of about 50 dogs barking. For some, it can be deafening.

“It doesn’t bother us anymore, we’re accustomed to it,” said McKnight, shelter manager of the Champaign County Humane Society. “People who come to visit are disturbed at first, but I think most people who come into an animal shelter expect the noise; I don’t think it deters them from adopting.”

Though staff of the Champaign County Humane Society may be able to adjust to the noise, and shell-shocked visitors can leave before the noise has any ill effects, the dogs in the shelter are far more sensitive to the noise. According to a recent study, “Noise in the Animal Shelter Environment: Building Design and the Effects of Daily Noise Exposure” from Colorado State University, noise in dog kennels may be a welfare concern for the animals, but currently no policies regulate noise levels in dog kennels. And dogs don’t have the option of wearing ear plugs.

“It is well understood and widely acknowledged that noise increases stress in animals,” said Crista Coppola, Ph.D., of the American Society for the Prevention of Cruelty to Animals and the Animal Behavior Center at the University. “Yet sound levels in shelters regularly exceed 100 decibels, which is comparable to the noise produced by a jackhammer.”

The way shelters are designed has an impact on noise level.

“If dogs are housed together, they vocalize less,” Coppola said. “Dogs are a very social species, and when they see each other and can’t interact with one another, they get very frustrated and begin to bark. Their welfare is reduced by living in this environment.”

The study also examined ways to decrease noise levels in animal shelters.

“It would be great if they could implement noise-absorbing materials into the building, but that is costly and harder to clean,” she said.

According to the study, there is little attention paid to noise abatement in new facility design, despite the evidence that noise causes physical and psychological stress on dogs.

The researchers found that dogs constantly bark in shelters where their cages are facing each other. Because any activity within the area stimulates the dogs, they also engage in frustration barking. However, when facilities are designed so that dogs are housed in self-contained rooms together, they engage in less barking and the noise is much better absorbed.

To meet the behavioral and physical needs of the animals, kennel design should ideally incorporate sound-absorbing materials and house dogs together, according to the study. This way, the study explains, they will not bark for lack of interaction.

The study found that the effects of poor kennel design are twofold. The animals’ mental and physical states are compromised, and the shelter employees may develop hearing damage and poor states of mind in caring for the animals.

While McKnight did not observe any visitors who had trouble staying at the shelter due to the high noise level, other shelters may not be designed as well. The researchers at Colorado observed that visitors sometimes are so bothered by the noise levels that visiting time is reduced during their search for an animal to adopt.