Boasting refined audio senses comparable with the finely-tuned palette of a wine connoisseur or the olfactory expertise of a ‘nose’ in the perfume industry, the highly-prized “Golden Ears” team have been enlisted in preference to any technological wizardry. Their mission is to ensure the high standard of quality over today’s voice network is matched when BT switches over to its IP based 21st Century Network (21CN).
Collectively, the team – based at BT’s labs at Adastral Park, Ipswich – have more than fifty years experience in voice quality testing for telephone networks and equipment. They can claim a long and distinguished tradition in voice quality dating back to a dictum from the Postmaster General in 1912.
Andy Heron, senior project manager for voice quality engineering, said: “Despite the growth of new services in the telecoms industry, for many customers voice is, and will remain, the most important communications service. In making the transition to the 21st Century Network it’s imperative that we get the voice quality right and the specialist skills of ‘Golden Ears’ testing is a key part of that. There are jokes made about the Golden Ears tag but it’s not about developing Superman-like hearing where you can hear a pin drop at five miles – it’s more about being able to recognise, identify and determine the cause of the most subtle changes which would be imperceptible to most users.
“You can’t learn it overnight and it takes a combination of a degree of natural aptitude and a great deal of experience to hone these skills to be able to detect and distinguish subtle variations in the quality and clarity of voice carried over a telephone line. It’s not the only way we test voice quality but it is extremely useful and important. These are vital skills which we don’t want to lose over time and we’re training up others in the team to join the ranks of the Golden Ears.”
As BT moves to develop 21CN the range of testing conducted by BTs voice quality specialists plays a key role in preparing for the switch over from the current PSTN which begins in the Cardiff area in late 2006.
For automated quality testing and network monitoring, BT is employing sophisticated tools and techniques with voice testing performed under many different network and environmental conditions. The testing of voice quality in an IP network environment is underpinned by the company’s experience in delivering high-quality IP VPN services and in monitoring quality of service on them.
Andy Heron added: “We have an array of technology to do the scientific measurement, but its human voices we’re carrying across our network and human ears listening at the other end - the human experience and perception is all important. That’s why we also do subjective testing using ‘real people’– a cross section of the telephone-using public - who do not have any in-depth experience or knowledge of these systems.”
In the UK, BT’s 21CN involves the migration of 30 million customer lines and the withdrawal of the legacy voice (PSTN) platform. 21CN will deliver today’s and future services sending them through one dedicated IP network. This £10billion programme is expected to be completed by the end of the decade.