How do we improve audio quality?

Read how Spearline measures the audio quality of your toll and toll-free numbers...
On Thursday 18 May 2017 by Matthew Lawlor

One of the first questions our clients ask us is what are the benefits of number testing?


It’s a good question.

Our clients have a good appreciation for the sophistication of systems used for telecommunications worldwide. Most will spend a good deal of time and money ensuring their systems have the necessary features in place to deal with failures and downtime, but many lack visibility of the precise paths their calls are taking outside of their own infrastructure, and the audio quality of the calls their users experience.

The Spearline Platform first measures the audio quality of the call using in-country servers and an international standard audio quality measurement known as PESQ. The audio quality score is then benchmarked against the millions of tests we have carried out in over 60 countries worldwide. We can then advise the quality score they should expect to achieve and help them achieve it.



One of our clients had a product that allowed users to dial into a meeting using a PTSN or softphone. Many of the users reported call quality issues. Spearline reccomended running an Audio Quality test to pinpoint the cause of the issue. During the initial tests, the average audio quality PESQ (Perceptual Evaluation of Speech Quality) score was 2.74 (out of a maximum of 4.5).

In addition to our Audio Quality test, we developed an application specifically for this client to take control of the soundcard of a PC allowing us to send/receive audio to/from the softphone. Step by step we suggested changes to improve the audio quality and measured the improvement after each step. We were also able to advise the customer to tailor their maintenance schedules to avoid similar problems in the future which had been a factor in the poor audio quality.

The client saw an increase in the average audio quality from 2.74 up to 3.78 on the PESQ scale an increase of 38%. Users consequently reported a dramatic improvement in the audio quality of their calls. The client has undertaken a development programme of incorporating better quality codecs to increase call quality further and we continue to run scheduled automated tests to report back to the customer on the effectiveness of the solution for the end user audio quality of the call.

Typically, these problems arise from a number of different sources and therefore the resolution is an ongoing process in what is a dynamic environment with a large number of variables. 

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