Factors Affecting Contact Centre Audio Quality

Factors when measuring call quality on toll and toll-free numbers worldwide
On Wednesday 30 September 2015 by Kevin Buckley

Spearline measures call quality on toll and toll-free numbers worldwide. The need to measure the audio quality of calls may seem  self-evident but you’d be surprised how many companies fail to take this into account when assessing their overall quality of customer experience. Of course, amongst the biggest users of international toll and toll-free number systems are Contact Centres.



The sheer complexity of Business Process Outsourcing (BPO) services has made it difficult for the technological factors to be assessed when deciding on the impact on call centre staff and their effectiveness. Up until relatively recently, companies were unable to assess overseas toll and toll-free numbers other than to measure the effectiveness of the computer networks that were at the heart of the technology. Standard measurements of packet loss, jitter and latency within these networks are typically used to measure quality.

However, the actual audio quality of calls cannot be accurately measured using these criteria and as a result Spearline developed their proDial test to include an audio quality algorithm based on the international standard Perceptual Evaluation of Speech Quality (PESQ).

Common quality measurements in Contact Centre agent evaluation

  • Number of calls handled per hour
  • Time taken to deal with calls
  • First call resolution score
  • Customer satisfaction
  • Abandoned calls
  • Employee turnover


If one looks at each of these representative metrics (only a handful of the many used across many different industries) you can see that there are many different factors which can affect the outcomes.

For instance, the number of calls handled per hour could vary widely depending on the type of industry involved. A call to a financial advisor helpline or mortgage company where selling a financial instrument or mortgage is involved could conceivably take on average, much longer than a call to book an appointment to see a doctor. However within the same industry the call length should be easier to define.

Audio quality as a factor

Surprisingly there appears to be almost no research within the industry around the question of audio quality of the calls. If there is, the research normally relates to the environment in which the call centre agents operate, acoustic shielding, noise cancelling headphones etc.

Almost no one mentions the actual quality of the sound transmitted during the call. Yet anyone who has made an overseas call especially using VoIP will have noted multiple occasions when the audio quality was so poor it caused them to have a prolonged conversation or indeed to give up and try again.

Inability to measure audio quality

We suspect the reason is that very few companies have been able to measure accurately the audio quality of high volumes of calls. Spearline believe that any of the above mentioned factors have an audio quality component which is vital to measure in order to improve productivity and quality outcomes.

proDial Quality Test

Spearline provides the opportunity to companies all over the world using BPO to measure this audio quality. The measurements are taken using in-country calls and the quality is benchmarked against a dataset of millions of tests to date. The tests give an accurate reflection of the customer/contact centre interaction from an audio quality point of view including recordings of each and every test made.

The tests are automatically scheduled, cloud based and have a reporting system that can be tailored to each companied requirements. In addition, Spearline offers a complete managed service including, testing, reporting, fixing and maintenance advice in order to maximise quality across your entire system wherever you are in the world.

Free trial

Spearline offers a free trial to all our new customers so that you can prove the concept on your network and your toll and toll-free numbers. Try it today.