Klipsch R6i (wired) headphones drops volume without my input
I purchased the Klipsch R6i headphones (wired). I've noticed while playing music from Apple Music and Spotify, the headphones automatically lower the volume without my input. I will place the volume at max, put the phone down, and can actually see the volume drop without any of my doing. In an attempt to remediate the issue, I have done a clean install of the iOS software (v9.3.1) and then restored from a recent backup. The issue still occurs. What else can I do to resolve this matter? Any help will do.
iPhone 6, iOS 9.3.1