Auckland-based Digital Technologies (DTL) should receive the prototype for its broadband noise suppression system within the next week.
DTL received a grant from Technology New Zealand earlier this year to develop what it was then calling a Smart Sound Active Headphone. Now named Q|Sonix, the product uses digital technology, rather than traditional analogue feedback configurations, to reduce noise.
The system is aimed at the aviation market and includes a light-weight active headphone/set which connects to DTL's digital controller. The controller uses a digital signal processor with embedded software.
DTL founder Mark Donaldson says the software is based on modern optimal control theory. "It's just an algorithm, which is quite straightforward. In terms of the software itself it would only be 10 to 50 lines."
The chip processes the Q|Sonix algorithm at over 60 million instructions per second per channel.
Donaldson says he expects the prototype system to be delivered from a manufacturer in Christchurch within the next week. After the product has been tested, he hopes it will be ready within two months.
The product aims to create an "inverse replica" of the acoustic noise that's propagating in space.
"If you've got a noise signal, imagine it as an up-and-down wave. We're trying to create the mirror image of that," says Donaldson.
He says when the anti-noise and the noise are put together, it yields close to a flat line, which basically means zero sound. The concept is fairly well established, but what DTL is doing is using a novel digital controller.
"Active noise reduction is a method of noise control that's seen a lot of work in research and development in tertiary institutions. But its proliferation commercially has been quite restricted, basically because its cost-effectiveness hasn't been sufficient.
"What we're trying to do with the use of digital technologies is provide an effective solution for the reduction of low-frequency noise."
He says there is already interest in the product from commercial aerospace (primarily commercial air transport), defence and general industry.
"This particular system is specifically designed for in-flight entertainment and headphones or headsets in aircraft, but the general technology could be applied across the board."
He says people are interested in fast jet and helicopter helmets, field communications and perhaps a hearing protection type of application.
The market, he believes, will mainly be international.
Following publicity after the Technology New Zealand grant earlier this year, Donaldson fielded many enquires. "We've had calls from people worried about anything from the noise in pinball machines to the noise from 16-cylinder gas fired turbines. There have been quite a few inquires from offshore. People seem to have a lot of problems with noise wherever you look."
Donaldson did some work on the concept for his Masters degree (in mechanical control systems) at university two years ago.
He started up DTL with a business partner over the last year. Donaldson is based at Ardmore, and his business partner is based at Patumahoe.