Acoustical coupler

Claim 1

SOUND COUPLING APPARATUS COMPRISING: FIRST AND SECOND TRANSDUCER UNITS, ONE OF SAID UNITS INCLUDING SOUND TRANSLATING MEANS OF THE TYPE OPERABLE BY ELECTRICAL INPUT SIGNALS TO PRODUCE CORRESPONDING SOUND SIGNALS, THE OTHER OF SAID UNITS INCLUDING SOUND TRANSLATING MEANS OF THE TYPE OPERABLE BY SOUND SIGNALS TO PRODUCE CORRESPONDING ELECTRICAL OUTPUT SIGNALS; AN ACOUSTICAL COUPLER BETWEEN SAID TRANSDUCER UNITS TO TRANSFER SOUND ENERGY BETWEEN THE RESPECTIVE SOUND TRANSLATING MEANS THEREOF, SAID COUPLER INCLUDING A FIRST PART OF GENERALLY CUP-SHAPED CONFIGURATION AND PROVIDED WITH A FIRST ENGAGEMENT SURFACE AROUND THE MOUTH OF THE CUP, SAID ENGAGEMENT SURFACE BEING ENGAGED WITH A CORRESPONDING SURFACE OF SAID FIRST TRANSDUCER UNIT, THE SOUND TRANSLATING MEANS OF SAID FIRST TRANSDUCER UNIT BEING POSITIONED ADJACENT THE MOUTH OF SAID CUP-SHAPED PART TO SERVE AS ONE WALL OF A FIRST CAVITY WITHIN THE INTERIOR SPACES OF SAID CUP-SHAPED PART; SAID CUP-SHAPED PART BEING PROVIDED WITH A PASSAGEWAY ONE END OF WHICH COMMUNICATES WITH SAID FIRST CAVITY NEAR THE BOTTOM OF THE CUP AT LEAST APPROXIMATELY OPPOSITE THE SOUND TRANSLATING MEANS OF SAID FIRST TRANSDUCER UNIT, SAID PASSAGEWAY HAVING A SMALL CROSS-SECTIONAL AREA ADAPTED TO CONDUCT SOUND ENERGY; SAID COUPLER FURTHER INCLUDING A SECOND PART INTEGRAL WITH SAID CUP-SHAPED PART AND PRESENTING A SECOND ENGAGEMENT SURFACE SURROUNDING THE OTHER END OF SAID SMALL PASSAGEWAY, SAID SECOND ENGAGEMENT SURFACE BEING ENGAGED WITH A CORRESPONSING SURFACE OF SAID SECOND TRANSDUCER UNIT, SAID SECOND TRANSDUCER UNIT BEING FORMED TO DEFINE A SECOND CAVITY WITH THE SOUND TRANSLATING MEANS OF SAID SECOND TRANSDUCER UNIT SERVING AS ONE WALL OF SAID SECOND CAVITY OPPOSITE SAID OTHER END OF SAID SMALL PASSAGEWAY, SAID FIRST AND SECOND CAVITIES HAVING CROSS-SECTIONAL AREAS SUBSTANTIALLY GREATER THAN THAT OF SAID PASSAGEWAY AND PROVIDING ACOUSTIC COMMUNICATION BETWEEN BOTH SOUND TRANSLATING MEANS THROUGH SAID PASSAGEWAY.