Featured Research

from universities, journals, and other organizations

Sonar System For The Blind

Date:
June 26, 2008
Source:
American Institute of Physics
Summary:
Animals use echolocation for hunting and navigation, but visually impaired humans also employ echolocation as part of their orienting repertoire while navigating the world. There are a few rare individuals who can echolocate very well without assistance. However, researchers at Boston University have developed a prototype device that can enhance auditory cues while navigating an environment.

Echolocation is a method of perceiving the world by emitting noises, then listening to the reflections of these noises off objects in the environment. Animals use echolocation for hunting and navigation, but visually impaired humans also employ echolocation as part of their orienting repertoire while navigating the world. There are a few rare individuals who can echolocate very well without assistance.

However, researchers at Boston University have developed a prototype device that can enhance auditory cues while navigating an environment. The device repeatedly emits an inaudible (to humans) ultrasonic click several times per second, and each click reflects off any objects in the environment. The reflections are then detected by special head-mounted microphones, and computer processing converts the ultrasonic signals into audible signals, which the user then can hear over custom open-ear earphones.

The end result is an "auditory image" in which objects in the environment seem to emit "sounds" to the user, with objects of different shapes and textures emitting subtly different sounds, such that the user can distinguish between them. According to BU researcher Cameron Morland, the unique acoustic characteristics of the reflections enable the user to better distinguish the location and size "surface" properties of objects. For instance, sounds emitted by an object to the left will arrive at the left ear a bit sooner and louder (interaural time difference and interaural level difference).

Furthermore, sweeping the device over a surface while remaining the same distance from it, will produce a reflection with unchanged velocity of the surface of an object is flat. If the surface is tilted so it moves closer to the user, it will sound higher in pitch; tilted the other way, it will sound lower in pitch (a Doppler shift). A roughly textured surface will have some regions that are closer, and others that are further away, and users can easily learn to recognize those differences, and discern the resulting pattern of increased and decreased pitch. "Venetian blinds sound quite different than a flat surface, or a bookshelf packed with different-sized books," says Morland.

The BU team has built a prototype capable of simple detection of objects and open spaces, and preliminary tests show that most people can echolocate a little using the device, and improve quickly with practice. They are now refining their prototype to function in more complex, real-world environments. Morland believes that given enough practice, people should be able to echolocate very well using the device - perhaps better than they could unassisted, since higher frequencies outside the normal range of human hearing are more useful for echolocation. (Movies of the device can be found at http://cns.bu.edu/~cjmorlan/research)

Their paper, "What it is like to be a bat: A sonar system for humans," will be presented at 5:20 p.m. on Tuesday, July 1 at Acoustics '08 Paris -- the largest meeting ever devoted to acoustical science, to be held Monday June 30 through Friday July 4 at the Palais de Congrθs in Paris, France.


Story Source:

The above story is based on materials provided by American Institute of Physics. Note: Materials may be edited for content and length.


Cite This Page:

American Institute of Physics. "Sonar System For The Blind." ScienceDaily. ScienceDaily, 26 June 2008. <www.sciencedaily.com/releases/2008/06/080625153404.htm>.
American Institute of Physics. (2008, June 26). Sonar System For The Blind. ScienceDaily. Retrieved September 2, 2014 from www.sciencedaily.com/releases/2008/06/080625153404.htm
American Institute of Physics. "Sonar System For The Blind." ScienceDaily. www.sciencedaily.com/releases/2008/06/080625153404.htm (accessed September 2, 2014).

Share This




More Health & Medicine News

Tuesday, September 2, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Get on Your Bike! London Cycling Popularity Soars Despite Danger

Get on Your Bike! London Cycling Popularity Soars Despite Danger

AFP (Sep. 1, 2014) — Wedged between buses, lorries and cars, cycling in London isn't for the faint hearted. Nevertheless the number of people choosing to bike in the British capital has doubled over the past 15 years. Duration: 02:27 Video provided by AFP
Powered by NewsLook.com
Can You Train Your Brain To Eat Healthy?

Can You Train Your Brain To Eat Healthy?

Newsy (Sep. 1, 2014) — New research says if you condition yourself to eat healthy foods, eventually you'll crave them instead of junk food. Video provided by Newsy
Powered by NewsLook.com
We've Got Mites Living In Our Faces And So Do You

We've Got Mites Living In Our Faces And So Do You

Newsy (Aug. 30, 2014) — A new study suggests 100 percent of adult humans (those over 18 years of age) have Demodex mites living in their faces. Video provided by Newsy
Powered by NewsLook.com
Liberia Continues Fight Against Ebola

Liberia Continues Fight Against Ebola

AFP (Aug. 30, 2014) — Authorities in Liberia try to stem the spread of the Ebola epidemic by raising awareness and setting up sanitation units for people to wash their hands. Duration: 00:41 Video provided by AFP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins