to ensure high directivity while directionality provides many advantages it is not ... listening situation and ensures that directionality will provide a benefit before enabling ... similarly the wearing of full time directional system provides an audible distortion ... the delta instrument protects the two directional microphones by reducing the velocity of ... the preservation of high frequency directionality in delta obtained by ensuring a ... port spacing of 9mm against a standard bte shell casing b multiband adaptive ... directionality to maximise speech understanding in ... noise we must make use of directional microphones the only proven method to ... speech understanding 11 the benefit of directionality with open fittings has however been ... eardrum thus reducing the benefit of directionality fortunately various reports 12 13 have ...