He found a way forward with echolocation, the same ability employed by dolphins, making clicks to hear sound reflections off obstacles. Dr Davies' AUDEO works much the same way.
The device exploits the reflective Doppler effect, emitting a continuous ultrasound signal that bounces off objects when the user moves.
Each solid object has a different auditory sound based on the speed of the user and direction of travel towards that object.
This allows them not only to identify a low-hanging branch ahead on a trail, but also distinguish it from other surrounding objects.
Dr Davies said echolocation was not taught because society did not accept people making strange sounds.
"But my device enables echolocation at a frequency that no one else can hear."
Ultrasonic technology has been developed as an aid for the blind before, but not to the point Dr Davies has brought it to.
"The current systems that are out there are based on a sonar signal that is sent out, and once it comes back to the user it is processed in such a way that the engineer decides what the user should hear," she told the Weekend Herald.
"That is counter-intuitive for most people, and it tends to take 50 to 60 hours of training."
Her device was designed as a pick-up-and-use application and aimed to complement, but not replace, aids such and canes or guide dogs.
She said users hear nothing when standing still - but then would hear obstacles as they began to move, with a Doppler effect created between them and the reflected obstacle.
"So if you are walking in a room, it really sounds like each object in the room is making a different sound."
The project has been boosted by AdviceFirst with a $5000 grant.
Blind Week runs from Tuesday to Monday week. To learn more and find out how to support the Royal New Zealand Foundation of the Blind, visit www.blindweek.org.nz
Removing obstacles one whoosh at a time
For Chris Orr, the ultrasonic "whooshing" sound he suddenly heard while walking through the Auckland Domain yesterday indicated more than a low-hanging branch he otherwise wouldn't have seen.
The Manurewa man - blind most of his life - is excited about the Kiwi-developed ultrasound aid for the visually impaired after taking it for a test run.
A manager at the Royal New Zealand Foundation of the Blind, Mr Orr considers himself a competent and independent traveller who would ordinarily use a guide dog to sense any hazards above waist height.
While he has dabbled with ultrasound technology before, using the AUDEO device was a new experience altogether.
"What the device was doing was giving me information in my ears through sound," he said.
"I could actually hear there were things around me I otherwise wouldn't have known were there."
He knew there were bushes either side of him, but it was a branch, which he sensed from about a metre away, that otherwise might have caught him out.
"All of a sudden there was a totally different noise - and that was the trick. It was pronounced that there was a new thing there ... something I had to be aware of."
Mr Orr said the technology hadn't yet been looked at by the foundation's experts, but he was keen to see it progress.
"Anything that can add to the independence of a blind person needs investigating, no matter what it is."
