Exemplary noise reducing methods and systems are configured to acoustically reproduce two electrical noise reducing signals at two opposing positions in a helmet; to pick up sound at positions in the vicinity of the positions where the noise reducing signals are reproduced; and to generate the two noise reducing signals from error-signals and reference-signals. For each noise reducing signal, the corresponding error-signal is generated from the sound picked-up at the same position where the respective noise reducing signal is reproduced; and the reference-signal is generated from the sound picked-up at the position where the respective other noise reducing signal is reproduced.

An adjustable helmet having first and second shells and a single actuator comprising at least one tooth, the single actuator being moveable between: a first locked position, wherein the at least one tooth retains the first and second shells and the first and second shells define a first hollow space; a released position, wherein the at least one tooth no longer retains the first and second shells such that one of the first and second shells is moveable relative to the other of the first and second shells; and a second locked position, wherein the at least one tooth retains the first and second shells and the first and second shells define a second hollow space, the second hollow space being different than the first hollow space.

An adjustable helmet having first and second shells and a single actuator comprising at least one tooth, the single actuator being moveable between: a first locked position, wherein the at least one tooth retains the first and second shells and the first and second shells define a first hollow space; a released position, wherein the at least one tooth no longer retains the first and second shells such that one of the first and second shells is moveable relative to the other of the first and second shells; and a second locked position, wherein the at least one tooth retains the first and second shells and the first and second shells define a second hollow space, the second hollow space being different than the first hollow space.

A coupling assembly for safety headwear is provided. The coupling assembly includes one or more apertures within safety headwear, such as a hard hat, and a coupling structure that couples to the one or more apertures. The coupling structure includes one or more surfaces that interface with the safety headwear. The coupling structure includes a protrusion that defines one or more widths, and the protrusion extends through the one or more apertures.

A ballistic helmet comprising a ballistic shell, wherein within the thickness of the ballistic shell, or inside the ballistic shell, there is provided one or more circuit layers forming a circuit, which circuit comprises a power bus and a data bus, and wherein one or more power connections and one or more data connections are provided on the inside and/or on an edge of the ballistic shell for providing power and data to/from one or more electrical devices through the circuit.

A plastic football helmet has a shell with a left earflap in a left side region and a right earflap in a right side region, each ear flap having a non-circular ear hole, and an offset area defined on a top edge by a top banked portion and on a bottom edge by a bottom banked portion, the offset area extending continuously from the right ear flap, across the rear region, to the left ear flap. The non-circular ear holes are in the offset area. Both the top edge and the bottom edge of the offset area curve upward from the right ear flap to the rear region and curve upward from the left ear flap to the rear region. The top edge and bottom edge do not meet at any point such that offset area begins at an open right end in the right earflap and ends at an open left end in the left earflap. Cheek support are attached to the earflaps to improve retention of the helmet and provide protection to the cheek area against blows.

A plastic football helmet has a shell with a left earflap in a left side region and a right earflap in a right side region, each ear flap having a non-circular ear hole, and an offset area defined on a top edge by a top banked portion and on a bottom edge by a bottom banked portion, the offset area extending continuously from the right ear flap, across the rear region, to the left ear flap. The non-circular ear holes are in the offset area. Both the top edge and the bottom edge of the offset area curve upward from the right ear flap to the rear region and curve upward from the left ear flap to the rear region. The top edge and bottom edge do not meet at any point such that offset area begins at an open right end in the right earflap and ends at an open left end in the left earflap. Cheek support are attached to the earflaps to improve retention of the helmet and provide protection to the cheek area against blows.

A soft-sided helmet may comprise a ventilation system having at least two radial vents, including a first radial vent and a second radial vent; at least a first air channel connecting the first radial vent to at least one other radial vent; and at least a second air channel connecting the second radial vent to at least one other radial vent. The first radial vent may oppose the second radial vent. The ventilation system may further comprise further radial vents, which optionally may be connected to each other via one or more air channels.

A soft-sided helmet may comprise a ventilation system having at least two radial vents, including a first radial vent and a second radial vent; at least a first air channel connecting the first radial vent to at least one other radial vent; and at least a second air channel connecting the second radial vent to at least one other radial vent. The first radial vent may oppose the second radial vent. The ventilation system may further comprise further radial vents, which optionally may be connected to each other via one or more air channels.

A helmet defining an opening for a user's head, the helmet including an outer shell providing a wave guide exit operatively associated with an integrated wave guide layer surrounded by the outer shell, the wave guide layer being adapted to direct sonic waves out the wave guide exit, thereby substantially preventing the sonic waves from penetrating through a remainder of the helmet to the opening. The wave guide layer may be a sonic wave transmission medium composed of acoustic metamaterial, wherein the wave guide layer communicates with the wave guide exit.