AJA have undertaken a variety of acoustic assessments at call centres in the UK, including those operated by Aviva, Centrica, Vodafone UK and AXA.

The principal acoustic challenge faced in call centres is high noise levels (usually as a result of dense population), reverberant conditions and inadequate acoustic screening between desks. While ambient noise levels may not be high enough to give rise to hearing damage, telephone headsets and handsets, particularly older systems, require a high signal-to-noise ratio for good intelligibility. This is much higher than is typically needed for normal acoustic speech. In noisy call centres, this can lead to agents turning up the audio on their telephone headsets to damaging levels, without being aware of the long term effect of doing so. High ambient noise levels can also impact on the quality of audio that the customer hears at the other end of the line.

Our assessments have included measuring ambient noise levels, advising on control of reverberation and improvement of screening between desks. We were appointed as part of Centrica’s T6 Transformation Programme, where we undertook “before and after” measurements of telephone headset audio at more than a dozen call centres throughout the UK. Telephone audio measurements were taken side-by-side with agents on live calls using a compact artificial ear rig.

In comparison to larger and more cumbersome head and torso simulators (HATS), this allows us to carry out our work quickly, with minimal disruption to working agents. We reported on changes in audio spectrum reproduction, acoustic signal-to-noise ratio and intelligibility between the new and old systems and advised on compliance with Noise at Work Regulations for agents.