A google image of a group of blind individuals hiking using echolocation.
Challenge
Echolocation helps blind people navigate new environments, but very few blind people can echolocate. One of the factors causing this is the inaccessibility of face-to-face echolocation instructors.
Approach
Virtual echolocation training programs can provide widely accessible training through simulation of virtual acoustic environments. A literature review of existing interventions and a user centered design approach is combined to develop an effective and interactive training program.
Solution
Using acoustic virtual reality and binaural spatialization by listening using a pair of headphones, I created an application to train visually impaired individuals to use echolocation for environmental awareness and navigation purposes. The application included acoustic simulations at a very high spatial resolution, and integrate a series of tasks of increasing difficulty in order to gradually train the user.
Virtual Acoustic Environment
In a virtual environment, we can design any room imaginable for training purposes. Factors such as ambient sound levels, room size, and surface materials can be easily altered compared to the real world. In this project, the loudness of the echo was adjusted to create varying difficulty levels.
An Interactive System Architecture
The system works by combining user sound input and sound data of a virtual room to enable the user to hear themselves in the virtual room. Interactivity was found to be important from the literature review. Hence, I enabled users to virtually rotate their head, input their voice, and control their character movement with keyboard keys.
Training Program
Training was designed in 5 environments inspired by an echolocation training package and interview with a blind echolocator. Environments presented common areas such as identifying corridor openings and concrete pillars.
Technical Development
To enable high quality real time rendering of the virtual environments, the acoustic data of the virtual rooms known as impulse responses were pre-calculated and stored.
Quantitative Analysis of Training Efficacy
Although training was done virtually, the improvement was assessed in the real world with 11 participants to enable higher correlation with real life echolocation ability. The study yielded a statistically significant improvement in echolocation ability.
