If you are listening to music on the earphone, Xmart Volume may help you turn down the music volume for a conversation. And then restore the music volume when the conversation finished. Perfect for "lazy" music lover!
Xmart Volume utilizes the built-in microphone of your Mac or iSight to perform "Active Volume Control" on your Mac!. It "listens" to the environment sound level and automatically turns down your headphone volume when it detects any sound which is louder than the background noise.