82 results about "Acoustical resistance" patented technology

A system for dissipating sound shock waves within a vehicle tire includes a wheel upon which a tire is mounted to create an internal air chamber defined by the wheel and the tire. A flow-resistant barrier is coupled to the wheel or the tire and defines an air cavity within the internal air chamber. The barrier comprises a material that provides an acoustical resistance to sound shock waves passing therethrough. The air cavity defined by the barrier has a volume such that air within the cavity offers relatively small impedance to the passage of shock waves through the barrier and into the air cavity. The barrier also can produce frictional heat when displaced by a shock wave, thereby converting energy of the shock wave to heat to reduce noise associated therewith.

Systems, apparatus and methods are discussed for controlling resonance in in-the-ear headphones. Resonance effects resulting from wave reflection and superposition can occur in the cavity formed by the port tube of an earbud and the wearer's ear canal. In this invention, acoustically resistive structures are provided to create sound diffusion in the cavity. In one embodiment, a spring coil with several adjustable parameters is inserted into the port tube. In another embodiment, a pattern of grooves is carved into the inner surface of the port tube. Porous filters can also be used in conjunction with both of the embodiments described above. The result of providing the resistive structures in an earbud is a flattened cavity frequency response and improved sound quality.

In one embodiment, an apparatus includes a graphic display panel and a speaker. The panel has a display layer for displaying images and defines a plurality of holes penetrating at least the display layer. The speaker includes a diaphragm arranged substantially parallel to the display layer. Sound from the speaker diaphragm is directed out of the host device through the holes. Speakers can be electret or piezoelectric speakers for thinness. There may be holes on the opposite side of the host device case for a dipole pattern that is directional and gives acoustic privacy to the user, or a rear acoustic cavity for a monopole pattern that is wider Disperse the sound. One illustrated embodiment is selectable between monopole and dipole. The size and total area of ​​the apertures determine the acoustic resistance, so a method for determining them from the physical parameters of the display panel is described.

The embodiment of the invention relates to the field of noise protection, and discloses earmuffs and a noise reduction method by earmuffs. In the invention, the earmuffs comprise at least one cover, asound collecting module, an acoustic foam, a compressing device and a processing unit. The sound collecting module collects the environment noise and obtains the noise amplitude value of the environment noise. The acoustic foam creates acoustic resistance in the cover. The compressing device is used for compressing the acoustic foam in the cover to change the sound resistance in the cover. The processing unit is separately electrically connected with the compressing device and the sound collecting module and pre-stores the preset amplitude value of the environment noise. The processing unit acquires the noise amplitude value obtained by the sound collecting module and calculates a desired resistance value of the acoustic resistance required for reducing the noise amplitude value to the preset amplitude value according to the noise amplitude value. The processing unit further controls the compression amount when the compressing device compresses the acoustic foam according to the desired resistance value. Thus, the acoustic resistance is increased when the acoustic foam is compressed to reduce the environment noise to the preset amplitude value, so that the noise is effectively reduced to reduce the harm to human ears.