Human echolocation in different situations and rooms: Threshold values

People, especially when blind, use echolocation to detect obstacles, orient themselves and get an awareness of their environment. Echolocation describes how people use reflected sounds to obtain information about their ambient world. Echolocation with long canes while walking is possible but difficult. Different spectral composition of the emitted sounds from canes had no differential effects. Sound recordings in anechoic and conference rooms from non-walking, static situations, later presented in a laboratory showed a better performance in an ordinary room with reflections, than in an anechoic room. Longer sounding sounds resulted in a higher performance than short clicks. Among the difficulties for the blind are how to avoid masking of sounds. There may exist a time gap, acoustic gaze, for how blind people use clicks. The results of previous studies were reanalyzed by using auditory models. Thresholds based on local non-parametric fitting, were determined for distance, pitch, loudness and sharpness. The...