Ever wondered about those dog whistles that don't make any sound? Do they really work, and if so, how do they work?
They do work, and it's because dogs' hearing is different from ours. Those whistles make a shrill that is at a higher pitch than the human ear can hear well, but that can be heard by the canine ear.
Hearing is an important part of a sporting dog's ability to work as they receive voice commands and instructions from the trainer and or hunter. Damage to hearing can affect performance by limiting a dog's ability to respond to commands and awareness of game in the area.
We know that chronic exposure to loud noises, such as gun blasts, can injure the sensitive workings of the inner ear, damaging hearing. It is not uncommon for retrievers to be located very close to gunfire while afield as they cue off us to locate and retrieve birds. Boats and blinds are generally tight quarters placing our dog's hearing in potentially damaging proximity to gun noise.
Or consider the bird dog that works a bird that holds tight to its cover. You might be almost directly on top of your dog before that bird flushes, placing your dog dangerously close to the muzzle blast.
Because of this, many knowledgeable owners and trainers have concerns about the their dog's hearing. Even without considering the differences in human and dog hearing levels, it seems reasonable to question that if we should use ear muffling inserts or other devices to limit our exposure to gun blasts, is our dog's hearing being damaged also?
To determine what, if any, effects the environment of duck hunting has on hearing in retrievers, Mississippi State University conducted research into the concern. In their study, they tested Labrador retrievers that were used for duck hunting against pet Labradors whom had never been shot over.
There are many reasons that the hearing of dogs might degenerate. Typically, age itself can decrease hearing capacity as the physical structures in the inner ear degrade over time. Chronic exposure to some drugs can also lead to low-grade hearing problems, and in some cases complete deafness. Specifically, some ear preparations used to treat infections can damage hearing if used long-term or if they enter the middle or inner ear through a busted eardrum.
After these natural and commonly acquired causes for hearing loss were taken into consideration, the results from the study showed that the Labradors chronically exposed to gun blasts through routine duck hunting did in fact have a decrease in their hearing responses. Through testing of brain wave response to specific noise levels, these Labradors showed a three-fold decrease in ability to hear soft noises. Based on testing results, these hunting Labradors were not able to hear the whisper of a human voice.
As we learn more about this problem, hopefully we will be able institute methods to prevent hearing damage before it occurs.