Abstract: A DJ media player is provided. The DJ media player includes a display to show audio playback information; a platter used to control audio playback; one or more energy-storing devices; and a processor for responding to DJ media-player electrical-power loss. Responding to DJ media-player electrical-power loss includes storing electrical charge on energy-storing devices; sensing a disruption in electrical current supplied by a power source to the DJ media player; powering the DJ media player using the electrical charge on the energy-storing devices; and displaying a notification on a DJ media-player display that there was a disruption of power. Responding to electrical-power loss comprises performing a safe shutdown procedure for avoiding file and system corruption.

Abstract: A method for active noise cancellation in a volume generates a mathematical model of a noise process to be cancelled. Using the mathematical model, a noise signal in a next sample period is predicted from a measured noise signal. The predicted signal is inverted and applied to the volume. Destructive interference of the noise signal and the inverted signal cancels the noise in the volume.

Abstract: An ear seal is disclosed for use in a headset. The ear seal includes a flexible sheath that encloses and is in contact with flowable material. The flexible sheath includes a first surface that extends between inner and outer peripheral edges of an annular top. The first surface is adapted for contacting a user's head and includes an inner annular groove separating an inner annular surface portion from a crease inhibiting central annular surface portion, and an outer annular groove separating an outer annular surface portion from the crease inhibiting central annular surface portion.