Echolocating Distance by Moving and Stationary Listeners

Abstract

It has long been known that human listeners can echolocate a sound-reflecting surface as they walk toward it. There is also evidence that stationary listeners can determine the location, shape, and material of nearby surfaces from reflected sound. This research tested whether there is an advantage of listener movement for echolocating as has been found for localization of emitted sounds. Blindfolded participants were asked to echolocate a 3 × 6 ft wall while either moving or remaining stationary. After echolocating, the wall was removed, and participants were asked to walk to where the wall had been. Results showed that participants were somewhat more accurate with moving than stationary echolocation for some distances. A follow-up experiment confirmed that this moving advantage was not a function of a specific type of training or the multiple stationary positions available during moving echolocation. This subtle moving advantage might be a function of echoic time-to-arrival information.

Spectral information for detection of acoustic time to arrival

“…Because acoustic tau is able to provide unambiguous information about a sound source's TTA, it will be accurate across all spectral bands, speeds, and listening conditions. However, while previous research has demonstrated the sensitivity of human listeners to acoustic tau (e.g., Ashmead et al, 1995;Rosenblum et al 2000), other evidence has suggested that acoustic TTA judgments are biased by speed, truncation, and other factors (e.g., Lutfi & Wang, 1999;Gordon & Rosenblum, 2005;Rosenblum et , 2000). An interesting question is how spectrum might affect TTA judgments.…”

“…rise in intensity of a sound approaching a listener, can be used to support TTA judgments (Ashmead, Davis, & Northington, 1995;Lee, van der Weel, Hitchcock, Matejowski, & Pettigrew, 1992;Rosenblum et al, 1987;Rosenblum, Gordon, & Jarquin, 2000). In general, as a sound approaches a listener, it will increase in intensity at an exponential rate, with its peak intensity occurring at the position of the listener.…”

The Doppler effect is not what you think it is: Dramatic pitch change due to dynamic intensity change

“…Discrete changes in intensity and frequency often indicate entry of different sources, but continuous changes almost always indicate single-source continuity (Rogers & Bregman, 1998). Considerable research suggests that humans and animals also use rate and pattern of changing intensity to aid in navigation and judgments of auditory source localization (Ashmead, Davis, & Northington,1995;Lee, 1990;Lee & Simmons, 1995;Lee, van der Weel, Hitchcock, Matejowsky, & Pettigrew, 1992;Neuhoff, 1998Neuhoff, , 1999Neuhoff, , 2001Rosenblum, Gordon, & Jarquin, 2000;Russell & Turvey, 1999;Schenkman & Jansson, 1986;Shaw et al, 1991;Stoffregen & Pittenger, 1995). The interaction of pitch and loudness and the large magnitude of pitch change for continuous intensity stimuli suggest that dynamic pitch may enhance such localization judgments.…”

Correlation between vividness of visual imagery and echolocation ability in sighted, echo-naïve people

“…Ammons et al 1953;Worchel and Mauney 1951) and that reflected sound waves can provide skilled echolocators with a wealth of useful information about the reflecting object -e.g. position, distance, size, and density (for reviews see for example Schenkman and Nilsson 2010;Stoffregen and Pittenger 1995), as well as motion (Rosenblum et al 2000;Thaler et al 2013a). On a purely physical basis, information about these properties is carried through mono-and binaural variations in echo timing, spectrum (pitch) and intensity (loudness), and people may be able to exploit these variables for echolocation (Cotzin and Dallenbach 1950;Papadopoulos et al 2011;Rosenblum et al 2000;Schenkman and Nilsson 2010;Stoffregen and Pittenger 1995), though the use of one or the other acoustic variable may also depend on the echolocation task people engage in.…”