DSP-based speech processing aids teleconferencing

A revolutionary teleconferencing system that puts blind and partially sighted people in touch with each other has been developed for the RNIB by Chelston Call Systems.

A revolutionary new teleconferencing system that puts blind and partially sighted people in touch with each other has been developed for the Royal National Institute for the Blind (RNIB) by Chelston Call Systems using speech-processing resources from Aculab.

"The teleconferencing system was commissioned by RNIB for the launch of its groundbreaking new Talk and Support service, the first project of its kind in the world", explains Faye Matthews, strategic marketing manager at Aculab, a leading provider of enabling technology for the communications market.

"Launched in March 2002, it allows people taking part to use the phone to share ideas, support each other, gain information and learn to cope more easily with sight loss - from the comfort of their own homes".

To create the system, Chelston Call Systems supplied RNIB with an audio conferencing bridge with voice recording facilities, based on its CallHandler-720 platform, an open standards Windows NT based computer telephony system that offers open architecture and web browser based control.

"RNIB had the added challenge of helping blind and partially sighted people who also may have hearing difficulties, so quality of sound is crucial to them", says Mike Quelch, Director at Chelston Call Systems.

"With features such as automatic gain control and echo cancellation, Aculab's Prosody card was the natural choice to provide the digital signal processing (DSP) resources necessary".

One of the key advantages of Aculab's Prosody DSP resource platform is that it provides developers with high density speech processing in an extremely compact and flexible form.

With up to 256 channels of DSP processing in a single slot, Prosody is the ideal choice for high density conferencing solutions, whether it is used for a single large, multiparty conference or many simultaneous separate conferences.

Its flexibility and performance means it is a very cost effective solution for this valuable and innovative service.

As well as stipulating that the conference bridge needed to be controlled over its LAN, RNIB asked Chelston to develop a special interface that could be operated by blind and partially sighted volunteers.

Another criterion was that conference facilitators needed to be able to be located within RNIB's WAN telephone network or be home based, with office based controllers who could conference into the call.

They could offer individual support to conference participants, but take them offline into a separate area for one-to-one conversation when necessary.

"Another major challenge was the fact that the management and setting up of teleconferences needed to be fully accessible and operational for visually blind and partially sighted users", adds Mike Quelch.

Because its CallHander-720 is standards based with productive programming interfaces such as C++ and Visual Basic, Chelston Call Systems was able to prototype a suitable graphical user interface quickly.

Additional in-built facilities include automatic and manual dial-in and voting facilities for participants.

Also integration with internal databases and full call reporting including billing are offered.

"The technology is easy to use and enables us to connect everyone in the conference call quickly and without too much interruption to the participants", says Julie Polzerova, project manager at RNIB.

"The software offers us the flexibility to manage the conference calls effectively, for example, individually tailoring the sound levels so that each participant is able to hear each other comfortably".

Aimed at blind and partially sighted people who find it hard to get out and about and those who feel isolated, the system has the capacity to offer teleconferencing services 24 hours a day, 52 weeks a year.

According to recent research, there are almost two million blind and partially sighted people in the UK, and 90% of these are over 60 years old.

The Talk and Support project has been created thanks to a generous donation of GBP 1.1 million from Barclays Bank which will fund the project for three years before it becomes self-financing.

Still in its pilot phase with plans to become nationwide by 2004, the service is already changing the lives of its participants beyond expectations.

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