Protecting military dogs' hearing with flexible materials

Materials World magazine
6 Jan 2020

A new type of flexible wearable gear helps protect the sensitive hearing of military dogs.

Military dogs’ hearing will be better protected in the field by using a new type of head gear made from lightweight and flexible materials, enabling a secure and comfortable fit around the head. The kit is intended to protect hearing during travel via helicopters, aircrafts, trailers, and in situations involving explosions and shooting.

The canine auditory protection system (CAPS) was developed by Zeteo Tech Inc, USA, in collaboration with retired Navy Lieutenant Commander and Professor at the University of Cincinnati, USA, Pete Scheifele.

Keeping working dogs safe is important ‘so that the hearing is not damaged permanently or temporarily, thus protecting the effective use of the dog in the battlefield and lengthening their service life,’ Scheifele told Materials World. ‘Protecting hearing is always important because audition is one of a dog’s special senses. It is directly involved with communication and limbic sensation of danger and cognitive decisions. Moreover, the mechanics of the ear are also linked to the vestibular system for balance – another of the six special senses.’

He added that although standard models of canine auditory protective gear are available, shortcomings were found for each model. ‘Some are built in such a way that sound can intrude around the device to the ear of the dog, and some have been produced but will not attenuate the frequencies that are most important to police or military dog.’

The new headgear, which appears similar to the common snood, is made using multiple lightweight materials. US Army Research Office Senior Scientist, Dr Stephen Lee, said ‘the sound-adsorbing material is added onto flexible materials that adapt to the dog’s head, ensuring a snug fit and thus better sound protection.’ At present, Lee was unable to give detailed information about the materials due to IP and development security, but confirmed that the gear is currently in commercialisation development.

To examine the equipment for attenuation abilities, it was tested at frequencies in a dog’s hearing spectrum in an audiology sound booth, Scheifele said. ‘After the material was tested, fit tests were done on a dog to be sure that no sound was entering the ear chamber from outside, and then the attenuation tests were re-run with the dog in the sound booth instrumented,’ he said.

Further, he explained that testing proved how much sound was reduced across the hearing threshold. ‘We were particularly interested in the ability of the material to attenuate low-frequency sounds from 30–1,000Hz. These are printable frequencies that the dog would be subjected to during transportation, gunfire and explosions.’

According to the scientists, the head gear can also treat noise phobia and potentially post-traumatic stress injuriesrelated to hearing, as well as being useful for day-to-day police dog operations.