How can I disable/enable the Voice Prompt on the Alto Solo headphones?

To disable the Voice Prompt, while not in a call, press and hold the call button and Volume Down button simultaneously for two seconds. Release the buttons when you hear "Voice Prompt Off," indicating that the Voice Prompt on the headphones has been successfully disabled.

To enable the Voice Prompt, while not in a call, press and hold the call button and Volume Up button simultaneously for two seconds. Release the buttons when you hear "Voice Prompt On," indicating that the Voice Prompt on the headphones has been successfully enabled.