About This Project

Like bats and dolphins, some blind humans are able to echolocate — using acoustic reflections to sense, interact with, and navigate the world. However, bats and dolphins echolocate ultrasonically, at frequencies that offer higher resolution but are inaudible to humans. Inspired by advances in computing technology, we are developing a simple, low-cost device that makes ultrasonic echolocation sounds audible and allows us to explore the most useful signal properties for human observers.

Ask the Scientists

What is the context of this research?

Environments like deep caves and murky water are too dark and silent for typical vision and hearing. Animals in these environments often have the ability to echolocate: They make sounds and listen for their reflections. Like turning on a flashlight in a dark room, echolocation “illuminates” objects and spaces actively using sound.

Some blind humans also echolocate using tongue clicks or cane taps. Human echolocation isn’t an exotic skill restricted to special individuals, but an innate mode of perception that can be developed with practice, and augmented by technology. For example, bats and dolphins echolocate at much finer resolution using ultrasonic frequencies. When slowed to be human-audible, ultrasonic echoes are also more informative than unprocessed audible echoes, at least to non-expert echolocators. Thus, in this project, we explore the benefits of assisted ultrasonic echolocation: how can a simple device make ultrasound echoes both audible and useful to a human listener?

What is the significance of this project?

For the blind and low-vision (BLV) community, everyday activities like navigating a room or commuting to work present significant challenges, especially in unfamiliar or dynamic environments. People often rely on sound for these essential activities, as it can provide information about the distal environment (beyond arm’s reach).

Blind human echolocators have well documented perceptual and navigational advantages over non-echolocators. At the same time, although sonar technology has been maturing for over a century, fuller adoption and benefits of sonar-based perceptual aids are limited. We would like to reconcile these facts by identifying the factors that limit or facilitate echolocation use; improve the evidence base for artificially and naturally mediated echolocation skills; and pave the way for a potentially transformative echolocation aid that may supplement, complement, or even substitute human instruction in resource-constrained training contexts.

What are the goals of the project?

With the project funding we're raising here, we have two main goals:

1. Recruit up to 30 blind and sighted study participants. In controlled computer-based experiments, they will identify or distinguish various object/scene echoes at different slowdown, pitch, or other attribute. This extends the lab's previous studies as well as our ongoing experiments, telling us which particular (combination of) settings are best for different tasks such as identification, navigation, etc.

2. Improve the hardware, e.g. upgrading the onboard processor or 3d-printed housings. An improved Robin makes cleaner signals and can be worn in more realistic experiments, making the results more practically interpretable.

3. Publish the results in an appropriate journal or conference proceedings, to benefit the public and wider research community.