Abstract: Disclosed is a navigation data translating method and arrangement. A translating device translates a destination data in an original format into a predetermined format, such as into American Standard Code for Information Interchange (ASCII). A communication device communicates the predetermined format to an offboard source that has navigation route data thereon. The communication device receives specific navigation route data from the offboard source in the predetermined format. The translating devices translates the received specific navigation route data into the original format type and sends the translated data onto an input/output device that disseminates the translated route data.

Abstract: A second-order differential (SOD) microphone includes a first-order differential (FOD) microphone element installed in a housing. A pair of front sound conduits extend from respective ports to a chamber on the front side of the microphone diaphragm, and a pair of rear sound conduits extend from respective ports to a chamber on the rear side of the microphone diaphragm. The two front ports and the two rear ports are all substantially collinear along a minor axis, with the rear ports intermediate the front ports or the front ports intermediate the rear ports. The respective acoustic transfer functions from each port to the microphone diaphragm are equivalent. The microphone response is approximately proportional to the second spatial derivative, along the minor axis, of a sample acoustic pressure field.

Abstract: A second-order differential (SOD) microphone includes a first-order differential (FOD) microphone element installed in a housing. A pair of front sound conduits extend from respective ports to a chamber on the front side of the microphone diaphragm, and a pair of rear sound conduits extend from respective ports to a chamber on the rear side of the microphone diaphragm. The two front ports and the two rear ports are all substantially collinear along a minor axis, with the rear ports intermediate the front ports or the front ports intermediate the rear ports. The respective acoustic transfer functions from each port to the microphone diaphragm are equivalent. The microphone response is approximately proportional to the second spatial derivative, along the minor axis, of a sampled acoustic pressure field.

Abstract: A radio or telephone handset configured with the usual transmitter and receiver ends and connecting handle is designed to have physical characteristics well adapted in its acoustic characteristics to complement noise cancellation circuitry. The receiver speaker is mounted in the receiver cap, and the cap is built with a domed, apertured earpiece extending from the exterior surface of said receiver cap. The dome fits into a user's outer ear, thereby to aid in positioning said handset on a user's ear. Openings radially placed on said receiver cap exterior surface and surrounding said earpiece, define an acoustic grill through which signal from said receiver speaker is passed substantially directly to said user's ear canal. Noise absorbing material is placed at strategic locations within the handset interior.

Abstract: Improved microphone performance is achieved by configuring a second-order derivative microphone assembly in such a way that radially divergent near-field input produces a microphone response proportional to a first-order spatial derivative of the acoustic pressure field.

Abstract: Telephone headsets used by operators and airline pilot headsets are subject to substantial amounts of interfering ambient noise which detract from the intelligibility of incoming speech. Noise reduction circuitry does not altogether eliminate the interfering sound. A headset speaker and error microphone housing are disclosed which enable a greater amount of unwanted noise elimination. The speaker and microphone are configured closely with respect to each other and also to the user's ear. They are acoustically isolated in their own chamber. The microphone is located approximately on the speaker axis and protrudes substantially into the user's ear; and also is disposed close to the speaker cone surface. Additional acoustical tuning features include venting ports in the housing, and acoustic damping padding at the microphone entrance and on either side of the speaker. These expedients enhance the ability of the noise-cancelling circuitry to effectively reduce the undesired noise heard by the user.