Peter Scheifele, director of bioacoustics research at the National Undersea Research Center, conducted a scientific study of deer whistles. Photo by Shannon McAvoy Scheifele, an animal bioacoustics and audiology expert, wanted to know more about the devices, so he and hisresearch team scientifically tested their effectiveness.

    The small plastic whistles, easily attached to car bumpers, hit the marketplace several years ago.  Some are sold for as little as five dollars. They vary in design, but their claims are relatively the same.Their manufacturers promote them as "acoustic attention-getters", alleging deer would react to the whistle by remaining still. "There has been a lot of conjecture about whether the whistles work or don't work, and we are one of the first independent groups to scientifically test them," says Scheifele, director of bioacoustic research at the National Undersea Research Center at Avery Point and a researcher in the Department of Animal Science.

He and his team tested six air-fed whistles in the laboratory and in the field. The study's goal was to determine the actual frequencies generated by the whistles and the intensity at which they are produced, compare that data to the hearing abilities of deer, and then take the animal's acoustic behavior into consideration. Following the directions on each package, the team mounted the devices onto a car's front bumper. Using a road closed to the public, they drove the car at speeds ranging from 30 to 45 miles per hour while recording sound and data.

     "We tested them strictly from an acoustical point of view," explains Scheifele. He found that the whistles typically produce a signal either at a frequency of 3 kilohertz (kHz) or 12 kHz. Both, as it turns out, are problematic.     The hearing range of white-tailed deer, the most common species in the United States, is between 2 kHz and 6 kHz, so the animal is not capable of hearing the 12 kHz signal.

     Although deer may be able to hear the 3 kHz signal, it is only 3 decibels louder than the road noise created by the car, so the signal is buried. Scheifele points out that the situation would be worse with additional traffic in the area or if the wind was blowing. "All in all, the air-fed whistles do not make sense to me acoustically, " states Scheifele.

     Since completing the study, a new electronic whistle has been put on the market. Although Scheifele has not had an opportunity to test it, he has examined its advertising claims. He says the specs for the electronic whistle are considerably different from those of the air-fed devices, so "there is a possibility that the electronic whistle is more effective than the air-fed devices." He has written a paper on his findings and submitted it to the Acoustical Society of America's Acoustics Research Letters Online where it will shortly be under review. So what is different about the Electronic Deer Whistle Deer Alert unit?

     The electronic Deer Whistle is engineered to produce both a sonic frequency (heard by humans and larger animals like deer and elk) and ultrasonic frequency (beyond the range of human hearing but heard by smaller animals) to alert animals of your vehicles presence. 

     The Electronic Deer Whistle has an effective range of 1,500 feet and is proven effective to work at any speed.

     The revolutionary new design incorporated in the Electronic Deer Whistle, Deer Alert unit ensures a tremendously effective device, which works with or without and maintenance to keep vehicle and it occupants safe from many of today’s road hazards.