port 202 which provides a connection for an audio signal from for example a radio a stereo or a communication system the audio port 202 may connect to electronics in each ear cup 110 via electric connection 206 each ear cup 110 may render the audio using for example a speaker or other type of sound driver built into the ear cup 110 additionally the audio system 208 may include electronics 210 that sense noise frequencies and actively cancel them in conjunction with speakers in each ear cup 110 in this way the benefits of the passive noise reduction system 118 may be combined with an active noise reduction system in some embodiments the electronics 210 components are mounted within the shell 102 of helmet 200 and may be isolated from the shell 102 by vibration dampening material activation switch 204 may activate or deactivate the electronics 210 of the active noise reduction system fig3 a is an exploded perspective view of the passive noise reduction system 118 from fig1 as described above the passive noise reduction system 118 includes ear cup 110 coupling 116 adjustment plate 114 and isolation mount 112 a the ear cup 110 which interfaces with the motorcyclist 39 s ear is mounted to coupling 116 which allows the ear cup 110 to rotate up or down i e about a horizontal axis the coupling 116 mounts to the adjustment plate 114 which allow the ear cup 110 to rotate side to side i e about a vertical axis accordingly this arrangement allows two degrees of freedom of the ear cup 110 which increases comfort for the user the isolation mount 112 a includes a receptacle 306 sized to receive the.