1. IN ACOUSTIC SIGNAL TRANSLATING APPARATUS IN WHICH ACOUSTIC BULK WAVES ARE PROPAGATED ALONG THE LENGTH OF A BODY OF PIEZOELECTRIC SEMICONDUCTIVE MATERIAL, A SYSTEM FOR TRANSDUCING BETWEEN SAID WAVES AND ELECTRICAL SIGNALS COMPRISING: AN ELECTRODE SYSTEM COMPOSED OF A PLURALITY OF ELECTRODE PAIRS SPACED SUCCESSIVELY ALONG THE LENGTH OF SAID BODY WITH THE INDIVIDUAL ELECTRODES OF EACH PAIR DISPOSED ON SPACE OPPOSED PORTIONS OF SAID BODY AND COUPLED IN COMMON AT THE FREQUENCY OF SAID WAVES, THE EVEN ONES OF SAID PAIRS BEING COUPLED IN COMMON AT SAID FREQUENCY AND THE ODD ONES OF SAID PAIRS BEING COUPLED IN COMMON AT SAID FREQUENCY WITH SAID ELECTRICAL SIGNALS BEING EXHIBITED BETWEEN SAID EVEN AND ODD PAIRS.