the sound collecting end due to the diffraction effect thus certain sounds are still collected and it is possible to totally block out the sounds when there is no film as in a the traditional microphone at the opening of the sound collecting end sound waves enter the sound collect opening in the transmission path which is not parallel with the sound collecting tube there would be multiple reflections and other disturbances occur on the tube 39 s wall various frequencies of reflections will cause various disturbances and cause sound distortions the invention 39 s structure employs one or more films but for the purpose of the following explanation only a single film will be discussed with respect to a film and its vibrations sound waves enter the tube in the transmitting path which is nearly parallel to the tube 39 s wall produces less multiple reflections thus there are no sound distortions when sound waves from a sound source comes at an incident angle u201c theta u201d to the surface of film 140 its sound wave arrives film a and b at difference time and the 2 films vibrate independently they could be seen as 2 new sound waves see fig5 which have the same wave form with but half amplitude of the sound source and there is the time difference and phase difference between the two new sound waves the 2 new waves combine as one sound wave in inner chamber 122 because of the phase difference between the 2 sound.