Calculation Of Human Echolocation Cues By Means Of The Boundary Element Method

Some visually impaired people are able to recognize their surroundings by emitting oral sounds and listening to the sound that is reflected at objects and walls. This is known as human echolocation. The present paper reports on the calculation of objective auditory cues present in human echolocation by means of the boundary element method using a spherical model of the human head in the presence of a reflecting disc at different positions. The studied frequency range is 100 Hz to 6.5 kHz. The results show that frequencies above 2 kHz provide information for localization of the object, whereas the lower frequency range might be used for size determination. It is also shown that stationary sound signals in echolocation can provide relevant acoustic cues, because displacements in the proximity of a reflecting object lead to frequency-dependent amplitude modulations.

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