Amazon filed for this patent for auto-muting headphones in July 2014. The device differs from similar products which have manual buttons to quickly mute music and disable noise cancelling because it is an automated system.
Amazon’s innovation has a series of microphones fitted into the earpads of the headphones which analyse ambient noise for cues that muting the headphones is appropriate. The device cuts out when specific sounds or phrases are heard for example when the wearer’s name is spoken or when there is suddenly around a lot of noise around which could spell potential danger for the wearer.
Source: http://buff.ly/2aJ3S4x