Abstract: A process of forming a sound needle for the scanning of mechanical sound carriers preferably records after the needle has been secured to a holder having a diameter comparable to the maximum diameter of the needle on the surface thereof opposite the needle tip and using a carrier having an opening therethrough, comprises reducing the diameter of the holder until it is a fraction of its original diameter, inserting the holder into the opening of the carrier and applying a securing material between the surface of the needle adjacent to and radially outwardly of the holder and to the carrier in the same area so as to secure the needle to the carrier, and reducing at least the major portion of the holder after the needle is secured to the carrier so as to leave only substantially a needle secured to the carrier.

Abstract: A vibrating member made of a thin metal plate and adapted to be used in an acoustic transducer such as a loudspeaker or microphone is diffused at least partially with an inorganic substance to improve the acoustic characteristics thereof, particularly the high frequency range.

Abstract: A needle for the acoustic sound box of old phonographs and gramophones is provided with a tip comprising a bearing plate which runs on the top surface of the recording on either side of a groove and a point which conforms to the groove. Both the bearing plate and the point comprise or consist of a low-friction polymer, especially polytetrafluoroethylene. The tip may be coated with the polymer or may be made therefrom, including the case where it deforms during playing to conform to the groove. The needle is especially useful in the re-recording of old cylinders and records using a microphone to capture the sound emanating from the horn or the phonograph or gramophone.