Canine Audiology: Noise Surveys and Distortion Product Otoacoustic Testing in Kenneled Canines.

Military Working Dogs (MWD) are placed in high levels of noise inside and outside their work activities. These hazardous noise levels have the potential to have adverse effects on the dog's auditory system. This study aimed to measure the typical kennel noise levels over a 24-hour period and conduct audiological testing on the MWDs. Most audiological testing is normed on humans but there is a need for canine norms. This study used four different distortion product otoacoustic emissions (DPOAE) protocols on 36 MWDs. The protocols varied in L1 /L2 intensity levels at L1=65dB, L2=65dB (DP65/65), L1=65dB, L2=55dB (DP65/55), L1=55dB, L2=55dB (DP55/55), and L1=55dB, L2=45dB (DP55/45). Descriptive statistics and one-way ANOVAs were used for analysis. Kennel noise exceeded the DoD hearing conservation program action level of 85 decibels A-weighting for humans. DPOAE testing showed that the largest amplitude responses came from the DP65/55 protocols. This is seen similarly in human DPOAE testing. DP65/55 reports a twofold advantage of producing higher DPOAE amplitudes with an improved sensitivity to cochlear mechanics. Optimal testing parameters allows veterinarians and audiologists to understanding the status of an MWD's auditory system and support in providing feedback regarding hearing abilities or hearing loss. [ABSTRACT FROM AUTHOR]