Public Release: 

Exploring the potential of human echolocation

Visually impaired people use the pitch, loudness and timbre of echoes to locate nearby objects

Acoustical Society of America

IMAGE

IMAGE: This is a diagram of echolocation testing. view more 

Credit: Kurt Vikman

WASHINGTON, D.C., June 25, 2017 -- People who are visually impaired will often use a cane to feel out their surroundings. With training and practice, people can learn to use the pitch, loudness and timbre of echoes from the cane or other sounds to navigate safely through the environment using echolocation.

Bo Schenkman, an associate professor at KTH Royal Institute of Technology in Stockholm, Sweden, will present a summary of some aspects of his work on human echolocation during Acoustics '17 Boston, the third joint meeting of the Acoustical Society of America and the European Acoustics Association being held June 25-29, in Boston, Massachusetts.

A better understanding of echolocation may improve methods for teaching the technique to people who have lost their sight later in life, and yield additional insights into human hearing. "Eventually I hope the research can give a result that can aid blind and visually impaired people," Schenkman said.

Many individuals who were born blind or who lost their sight early in life are highly skilled at using echoes that bounce off objects, walls, hallways and buildings to find their way around. The majority of people use the tapping of their canes to echolocate -- the action calls less attention to themselves. But others add their own sounds like clicking, shushing or snapping noises to detect objects around them.

In past research, Schenkman mostly used sound recordings to probe the ability of sighted and blind individuals to detect the source of echoes. By reanalyzing previously collected data using auditory models, he identified some of the specific informational cues that visually impaired people use to echolocate. The analysis shows that people use not only the pitch and loudness of echoes, which is well established, but that they may also use the timbre, especially the sharpness aspects of timbre.

His work shows that, on average, visually impaired people are better than sighted individuals at perceiving the sound quality of two sounds that are close together in time. Blind people can also more easily counteract the "precedence effect," a phenomenon that occurs when sounds overlap, and a person judges the location of the sounds to be from the location of the first arriving sound, rather than from the ones that arrive later.

Human echolocation shares some similarities with animal echolocation, though people use the skill to compensate for their sight, rather than as an additional sense. For both humans and bats, there is an ideal interval to emit sounds to most effectively echolocate. Humans, however, listen for the sound as well as its echo, while most bats seem to rely on just the echo.

"It's a byproduct of our hearing system that we can use echolocation, so we're not as proficient at it as bats," Schenkman said. However, "I think one can learn much from differences between humans and bats, to compare how the systems work."

Research into echolocation can inform Orientation and Mobility training, which helps people who are blind or visually impaired to navigate their environment. People who become blind early in life often learn to use their hearing, including echolocation, more efficiently. But for individuals who became impaired later in life, echolocation training can help them to move through the world with greater independence and safety.

###

Session 1aAAa1, "Human echolocation in different situations and rooms" by Bo N. Schenkman, is at 10:40-11:0 a.m. EDT, Sunday, June 25, 2017 in Room 207 of the John B. Hynes Veterans Memorial Convention Center.

MORE MEETING INFORMATION

Acoustics '17 Boston, the third joint meeting of the Acoustical Society of America and the European Acoustics Association.

The meeting is being held June 25-29, 2017 at the John B. Hynes Veterans Memorial Convention Center in Boston, Massachusetts.

USEFUL LINKS

Main meeting website: http://acousticalsociety.org/content/acoustics-17-boston

Technical program: http://acousticalsociety.org/content/program-acoustics-17-boston

Meeting/Hotel site: http://acousticalsociety.org/content/acoustics-17-boston#reservation

Press Room: http://acoustics.org

WORLD WIDE PRESS ROOM

In the coming weeks, ASA's World Wide Press Room will be updated with additional tips on dozens of newsworthy stories and with lay-language papers, which are 300-800 word summaries of presentations written by scientists for a general audience and accompanied by photos, audio, and video. You can visit the site during the meeting at: http://acoustics.org/world-wide-press-room/.

PRESS REGISTRATION

We will grant free registration to credentialed journalists and professional freelance journalists. If you are a reporter and would like to attend, contact Julia Majors (jmajors@aip.org) at AIP Media, 301-209-3090. For urgent requests, please contact media@aip.org who can also help with setting up interviews and obtaining images, sound clips, or background information.

LIVE MEDIA WEBCAST

A press briefing featuring will be webcast live from the conference on Monday, June 26, 2017 in the afternoon and Tuesday, June 27, 2017 in the morning in room 111 of the John B. Hynes Veterans Memorial Convention Center in Boston, Massachusetts.

Register at https://www1.webcastcanada.ca/webcast/registration/asa617.php to watch the live webcast. The schedule will be posted here as soon as it is available.

ABOUT THE ACOUSTICAL SOCIETY OF AMERICA

The Acoustical Society of America (ASA) is the premier international scientific society in acoustics devoted to the science and technology of sound. Its 7,000 members worldwide represent a broad spectrum of the study of acoustics. ASA publications include The Journal of the Acoustical Society of America (the world's leading journal on acoustics), Acoustics Today magazine, books, and standards on acoustics. The society also holds two major scientific meetings each year. For more information about ASA, visit our website at http://www.acousticalsociety.org.

ABOUT THE EUROPEAN ACOUSTICS ASSOCIATION

The European Acoustics Association (EAA) is a non-profit entity established in 1992 that includes in its membership societies predominantly in European countries interested in to promote development and progress of acoustics in its different aspects, its technologies and applications. EAA gathers 33 societies of acoustics and serves public citizens and more than 9000 individual members all over Europe with yearly events as well as scientific conferences and publications such as Acta Acustica united with Acustica and Acoustics in Practice. The European Acoustics Association (EAA) is an Affiliate Member of the International Commission for Acoustics (ICA) and of Initiative of Science in Europe ISE. Visit our website at https://euracoustics.org/.

Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.