Real-ear polar patterns and aided directional sensitivity.

Real-ear directional sensitivity patterns were obtained from a group of eight subjects wearing in-the-ear and completely-in-the-canal-placed microphones to determine whether depth of microphone placement within the ear affects electroacoustic estimates of directionality. Both conventional and extended versions of the Unidirectional Index and the Directivity Index were used to estimate directional sensitivity, and results indicated that depth of microphone placement affects directionality in a region-specific as well as a frequency-specific manner. Results also indicated that conclusions about directional sensitivity vary when assumptions about signal and noise source locations, the orientation of the listener relative to them, and human perceptual abilities are taken into consideration. Results are discussed in terms of the utility of modified estimates of directional sensitivity to quantify directional sensitivity when measurements are made in real ears and on possible localization and speech recognition effects that may vary with depth of microphone placement in a regionally specific manner.