Route both right and left channel audio source material into both earbuds, enabling users to hear both channels in each ear.
More Information #1More Information #2- Instructions: System Preferences > Accessibility > Audio > select “Play stereo audio as mono”
 - Device/Operating System : Mac OS X
 
- Instructions: Settings > General > Accessibility > Hearing > Turn on “Mono Audio”
 - Device/Operating System : iPhone
 - Other Info (if applicable): Information for iOS 12.4
 
- Instructions: Settings > General > Accessibility > Turn on “Mono Audio”
 - Device/Operating System : iPad
 
- Instructions: Settings > Accessibility > Hearing > select “Mono audio”
 - Device/Operating System : Android 5.1.1 (Lollipop) - Samsung Galaxy Note 4
 
