A headphone construction includes freely radiating sound converters whose diaphragms, when the earphones are attached, are not loaded by the impedance of the wearers' ear. The diaphragm of the electrostatic converter is primarily mass-inhibited and damped by acoustic or mechanical friction resistances. Supporting elements are provided between the head and the earpiece which provide minimum spacing distance between the diaphragm and the inlet of the ear which corresponds practically to the contact-free wearing of the sound converters. The supporting elements may advantageously comprise a pair of ring members which are concentrically arranged one within the other around the ear and which support the earphone at a spaced location from the ear. The rig members include openings which may be aligned and enlarged for varying the opening space defined between the diaphragm and the ear opening.
This invention concerns an ear protecting means and specially an ear-cap which protects the ear against dangerous noise. The object of the invention is to silence the dangerous noise while permitting talking communication between two persons. The invention consists of an ear-cap, which is placed against the exterior of an ear, and which includes a cushion which covers the ear and is of elastic and porous material, which transmits sound, the outside of said cushion being at least to its main part covered by a perforated disc, said disc defines a cavity which is closed beside the perforations, the thickness of said disc, the amount of perforations and their size and the volume of the cavity being adapted to the requested property of absorption of sound of a certain range of frequency.
4058688 - Headphone - Owned by Matsushita Electric Industrial Co., Ltd. (Osaka,JA)
A headphone capable of attaining binaural hearing giving substantially the same sound quality as one would expect from ordinary loudspeakers, said headphone having such sound pressure versus frequency characteristics that there are two peaks between 1.5 and 5 KHz and the level differences between the low level area and the peaks are limited within the range of 6 to 17 dB. The headphone leads the sound from a transducer through the outside as well as inside of the headphone to the ears.
A loudspeaker enclosure includes a rectangular cabinet having an acoustical port mounted in one of the vertical walls. A loudspeaker is installed in a bottom wall of the cabinet facing away from an interior volume of the cabinet. A highly resistive acoustic foam is positioned in front of the loudspeaker to restrict the direct radiation of the loudspeaker, so that the usable acoustic radiation emanates from the acoustical port.
An ear defender for a headset, the ear defender comprising a rigid shell having holes in a central portion to permit the passage of ambient sound and including a valve mechanism to close the holes as required. The shell consists essentially of a unitary construction, being formed as a one-piece moulding. The valve mechanism consists of a fixed plate and sliding plate both of which have holes which can be aligned to open the valve or misaligned to close the valve. The valve is mounted wholly within the shell so providing protection for the valve mechanism. Access to the valve and to other components within the shell is thus provided entirely from one side of the shell.
An audio transducer for a headphone includes ports which couple the rear of the transducer diaphragm to the interior of the cup. A resilient acoustic damping material is placed over the ports and is variably compressed by an adjustable clamp to provide a selectable frequency response curve. Two embodiments of the adjustable clamp are shown, as well as the coupling means which extends through an opening in the headphone cup to allow convenient adjustment by the user.
