Customers who call your contact center will assign a fundamental personality to the voice they hear and can be strongly influenced by its characteristics. Whether it’s a quick transaction they’re after, a sympathetic ear or just to be heard - voice quality really matters. But what if voice quality is bad and the call is full of echo, underwater or tinny sound effects? It can lead to frustrated customers and agents, transaction errors and increased call-handling time. All of which can reduce profitability and increase customer and agent churn. This short white paper takes a look at some of the reasons for poor voice quality and how to change that into ‘great voice quality’ to ensure you deliver the best service for customers and agents alike.

1. White Paper
Why voice quality
really matters in the
Contact Centre
by Sue Bradshaw, Technology Writer, Integrated Research
Equipped with the best training, skills and words, contact centre agents are on the front line of your business every day,
and integral to your success. And as your agents’ voices are their finest assets; it’s vital to protect their value. In a word:
Voice quality really matters.

2. What can cause poor voice quality?
A couple of days ago I had occasion to call my carrier about my bill. The
first person I spoke to was totally unintelligible – badly distorted, sounded
like a faulty microphone or something like that...
She could apparently understand me perfectly, and eventually transferred me to
someone else. This time there was no distortion, but the voice was so faint I could
barely hear her, and then only by her shouting into the microphone.
Not the first time I have had this sort of thing with call centres (not just my carrier).
I was wondering what causes this. Anyone?”
Source: Whirlpool Forum, 2011

3. I hope that wasn’t my contact centre!
This is not what you would want to hear about your call center is it? Apart from the impact on your reputation, poor
voice quality is bad for customer service and agent morale. And it’s costly too, because trying to undo the effects of
poor customer service, whatever the cause, is always more expensive than delivering a first-class customer experience
in the first place.
On the other hand good voice quality can subconsciously influence another person’s interaction with you and your
agents know how to use this to their advantage. How they sound has as much to do with their success as the words
that they speak.
But what if voice quality is bad and the call is full of echo, underwater or tinny sound effects? It can lead to
disappointed or frustrated customers (and agents), transaction errors and increased call-handling time. It may
increase the after-call work because some of the call’s elements weren’t clear and there’s the added perception that
the call center represents low value to the organization. All of which reduce profitability and can increase customer
and agent churn.
And as it’s vital to maximise customer retention and minimise agent churn, it’s important to ensure that all the
technology you’ve put in place to reduce background noise, ensure rapid population of ‘mash up’ screens, route calls
efficiently, gather speech analytics and so on, are all underpinned by good voice quality.
This short white paper takes a look at some of the reasons for poor voice quality and how to change that into ‘great
voice quality’ to ensure you deliver the best service for customers and agents alike.
What makes a good call?
There are many perspectives to take into account – for one caller it might be getting a rapid response with the right
information, having transactions or refunds handled promptly and politely with a quick positive outcome. For another it
might be making an enquiry or submitting feedback without having to wait half an hour to speak to an agent.
For the call center agent it’s the ability to hear the caller clearly and to rapidly access all the information they need
– likely to be spread across several systems, varying in age and technology. This enables them to bring everything
together to clear the call quickly with a successful outcome and minimal after-call work. It reduces the stress of dealing
with an unhappy customer and makes them more productive.
And for the contact centre manager – a call is the “moment of truth” between companies and their clients. It’s the
culmination of efficient workforce management and significant expense in technology, telecommunications, training,
human resources, office space and much more.
A quality customer-facing experience depends on many things working in harmony to meet KPIs and service level
agreements. At the heart of a complex interwoven fabric of infrastructure, human interactions, call routing, speech
analytics and call recording lies the critical factor that makes it all come together – the quality of the human voice.
What makes a bad call?
Alien, warped and garbled voices, underwater sound effects, choppy audio, voice distortion, hollow voice, echo,
overlapping conversations; the list goes on. These and many other impairments impact both agents and customers
significantly. It can lead to increased call length when customers and agents cannot understand each other and
are forced to repeat themselves. In many cases, customers will hang up and try again. Either way, these delays are
expensive to customer loyalty, agent productivity and increase the cost of a call.
Another contributor to a bad call is the agent’s inability to access the necessary information because the source data
is located on several different systems – resulting in lengthy delays populating the service screen. Waiting to log in
to several different systems and to possibly have to transfer a customer without their details can quickly turn a good
experience into a bad one. The performance of the infrastructure that supports these systems and the agent’s desktop
has a crucial influence on the quality of a call.
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4. Achieving quality customer service
Call quality monitoring
Call quality monitoring measures the agent’s ability to answer customer enquiries quickly and effectively, up-sell,
cross-sell, manage complaints and returns and so on. And performance monitoring includes tools and practices used to
detect any call-handling inefficiencies and drive individual and organizational improvement.
Quality and performance measurements include:
ÆÆ Greeting callers correctly
ÆÆ Following the defined call structure
ÆÆ Using agreed positive phases throughout the call
ÆÆ Abandoned calls – the lower the better
ÆÆ Calls answered
ÆÆ Average wait time
ÆÆ Grade of service
When used in conjunction with efficient work force management, speech analytics and other quality measurements, these
measurements provides invaluable insight into agents’ scheduling, performance and the resulting customer experience.
Dissatisfied customers will tell others, but nearly all of them don’t tell the contact centre, and the chances are high they
won’t come back. Attracting new customers is more expensive than retaining existing ones, and the same applies to
training agents and nurturing their morale.
Voice quality monitoring
On the other hand voice quality monitoring measures voice fidelity and identifies any impairments to it. It will show
you which part of the network is experiencing the classic enemies of voice quality – latency, packet loss and jitter, or
system degradation and failure and how those factors are influencing the Mean Opinion Score or MOS.
You can find an abundance of definitions for MOS; but simply put it is used to quantify voice quality, based on a scale
of 1-5, where 1 is low and 5 is high. 5 is like a face to face conversation, 4 is fair, when imperfections can be perceived
but sound is still clear, and is the benchmark for toll quality calls. As MOS degrades further to a value of 1 it can become
impossible to communicate.
Voice quality monitoring extends to the performance of the supporting PBX, trunk and gateway infrastructure and
configurations of route patterns, partitions, network regions, endpoints and so on. Quality VoIP even applies to silence!
Silence can be a wonderful tool for diffusing a situation, but if it’s filled with a static hiss, pops and clicks it’s not going
to help!
What can go wrong with voice quality?
Voice (and video) quality are measured in milliseconds (ms) not seconds
as is the case for unified communications applications like instant
messaging, email, presence, and in minutes for more traditional tasks
like file sharing, file transfer and printing.
It’s hard to imagine how short a millisecond is, but a general rule of
thumb is that a delay in speech of up to 100 ms is not detectable by the
human ear as an impairment. Once delay extends to 150 ms and above
the impact on voice quality is very noticeable. It’s hard to imagine how short a
millisecond is. A flash from a camera is
In the majority of cases, voice quality issues occur because of problems about a millisecond and a housefly’s wings
or conflicts within VoIP or between VoIP and other applications on flap once in about three milliseconds.
the network. Insufficient prioritized bandwidth, slow links, router
configuration errors, device failures and location bandwidth limits will It takes five milliseconds to blink your eyes.
all have an effect.
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5. Slow network links delay voice traffic
A link can be slow for many reasons, and congestion can be one of them although not necessarily the only one.
Whatever the cause, a slow link can delay voice packet delivery resulting in poor voice quality.
How can I measure delay?
Latency can be measured in a number of ways, and the most commonly used in VoIP is MOS. Once you can measure
the latency factor in MOS you can identify where it’s coming from and view it in dashboards or highlighted links on a
media-path diagnostics map. This shows the calls’ paths so you can correlate network performance with voice quality,
and with these points identified, you can analyze the causes.
The illustration on the left shows a network map of active voice streams on an
Avaya VoIP network. As devices involved in the call are discovered, classified
and monitored, slow links are identified instantly allowing you to focus on the
devices involved in impaired voice streams.
Once the voice streams are identified you can drill down to granular detail
and analyze the latency, packet loss and jitter experienced on any call. This
provides the insights you need to review quality of service settings and
bandwidth for any link that is experiencing latency. You might trace this to
VoIP configuration on the local or wide area network. For example, if a router
or firewall cannot pass the number of voice packets it receives without delay
and packet loss occurs, voice quality will be affected.
Latency is just one of the factors included in a MOS calculation. Other factors include lost packets and jitter (varying
amounts of delay between packets), codec, background noise, and loudness. As there are so many factors influencing
voice quality it’s not hard to see that it can be affected very easily. As a result, quality of service (QoS) needs to be in
place to ensure that voice packets receive higher priority than other non-real time traffic like email, instant messaging
and so on. The most common way to do this is to use Differentiated Services Code Point (DSCP) and mark voice packets
for expedited forwarding.
To make this successful it’s vital that every network device supports DSCP and provides the appropriate QoS treatment.
You can see from this requirement how important it is to view voice quality on a per hop basis. This is because all
may be well for most of the voice stream’s journey but if one hop does not honour expedited forwarding, then voice
quality is highly likely to suffer as it traverses that segment. And even if DSCP is implemented on every hop; if there is
insufficient bandwidth to honour QoS policies, the impact will still be felt.
Insufficient WAN bandwidth to honour QoS policies
If insufficient WAN bandwidth is available to support voice traffic, general network congestion is likely to result. This
can cause link latency with voice packets arriving late, out of order or being discarded; all of which impair voice quality.
As a lack of bandwidth is frequently perceived as the primary challenge to voice quality, the attempted remedy is often
to purchase more bandwidth in small incremental chunks. However, this approach may still not accommodate the
delay-sensitive, real-time demands of voice. A better approach is to measure existing call patterns to determine what
capacity may be required before adding more bandwidth.
If you can monitor VoIP network usage you’ll be able to establish the capacity you need to support your busiest
times, as well as the MOS cost per network hop and how the WAN is used to route calls to SIP trunks, PSTN gateways
and other destinations. By filtering only those calls experiencing quality impairments you can view voice quality
statistics including jitter, packet loss, latency and codec information and pinpoint exactly where in your network
congestion is occurring.
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6. To illustrate the impact of insufficient bandwidth for VoIP, recently a colleague received some help from a supplier – a
call she’d been eagerly anticipating. But the voice quality was very bad, most likely the equivalent in MOS terms of 1
based on her conversation. She said, “I’m struggling to hear you, can you just call back, the connection is really, really
bad. Look can you call me back? Is there anyway you can call me back? Do you want me to hang up now? There’s all
this squelching and constant background noise.”
This call took twice as long to resolve because of two reasons.
Firstly, the voice quality was so bad she had to ask the caller to call back.
And secondly when they called back she thought they wanted to have a
conversation about cycling, and was about to transfer the call to another
colleague - a very keen cyclist!
But no, the supplier had called to answer her query about ‘site links’.
Finally she said “Phew that’s much better, I can hear you now.”
This example illustrates how poor voice quality impacts everyone’s
productivity. It can create confusion in call handling, extend after call work
and require extra patience and energy for the customer and the agent.
In this example the supplier’s voice trunk was oversubscribed and the
congestion was affecting every route pattern using that particular gateway.
Why does bandwidth matter?
Congestion can happen for many reasons. VoIP configuration errors, location bandwidth limits or excessive gateway use
can all contribute to excessive bandwidth utilization. This is compounded if calls are configured to use a high bandwidth
codec such as G.711. When G.711 is used for VoIP it will give the best voice quality but the downside is that it takes
more bandwidth than other codecs, such as G.729.
This means that all available capacity to a particular location can quickly be consumed. This will result in poor voice
quality for all calls to and from that location. VoIP users will experience poor voice quality as voice streams compete
with each other and other types of traffic for bandwidth on the location’s link.
To prevent this happening, codecs can be chosen, and call admission controls can be used to protect voice traffic from
the negative effects of other active calls. Call admission controls can also reject calls when the volume exceeds specific
thresholds. This might also require a resetting of user expectations of quality when placing long distance calls or setting
service levels.
A failure has occurred!
What happens if a device fails on the primary route and insufficient bandwidth is available on the failover route? It’s
not good news! The addition of failed-over voice traffic is likely to cause route congestion that will have a noticeable
impact on voice quality and means that other applications also using the alternate route may be affected.
VoIP ecosystem management provides invaluable data when troubleshooting device failures. Firstly you’ll receive a
notification when degradation or failure occurs. You can choose the frequency of the alerts according to their severity
so you won’t be subjected to alert floods.
You’ll be able to drill down and view network interface details providing information about the links to and from the
interface such as IP addresses, utilization, duplex mode, link type and capacity, customer and site identifiers and any
packet loss sustained.
6

7. It’s also an invaluable tool for assessing voice quality and VoIP performance in general over the alternate route and
improving its capacity to cater for future events.
To assess the impact of a failover, active testing, or network assessment – can be used to check the performance of
VoIP with other application traffic on both primary and alternate routes. By simulating packets generated from voice
devices such as IP phones, voice gateways and voicemail servers, assessing engineers can observe how the network
responds to variations in voice traffic patterns. They can then determine what network adjustments should be made to
accommodate failover, usually in terms of QoS settings and link capacity.
Multi-channel contact centres
As the number of multi-channel contact centers increases and customer contact options expand to include e-mail, SMS
and web chat, the need to rely on multiple technologies increases the risk, but also the rewards.
As Unified Communications gain traction inside and outside call centres; providing the ability to manage more
customers in more ways, other factors will come into play.
These will include infrastructure monitoring to ensure that Unified Communications and Computer Enabled Business
Processes can deliver the efficiencies and choice they promise, as well as the return on investment (ROI) that comes
from increasing agents’ productivity and rapidly connecting customers with the right person and resources to manage
the call.
The success of your contact center is determined by the quality of the customer service it delivers, and its ROI. Voice
quality, abandoned and answered calls, together with average call length, gateway usage and capacity are insights you
need to identify performance excellence as well as performance exceptions.
The challenge is for you to monitor, measure and manage the components that make up the total quality of a
customer’s interaction with you, and overall to measure your call center’s operational success.
VoIP ecosystem management procedures and features will depend on the
platform being monitored. Contact us for more information prognosis.com/uc
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8. Contact us
Americas t: +1 (303) 390 8700 f: +1 (303) 390 8777 e: info.usa@ir.com
twitter.com/powerminder
Asia Pacific/Middle East/Africa t: +61 (2) 9966 1066 f: +61 (2) 9966 1042 e: info.ap@ir.com
United Kingdom t: +44 (0) 1344 894 200 f: +44 (0) 1344 890 851 e: info.europe@ir.com facebook.com/IntegratedResearch
Germany t: +49 (69) 710 455 255 f: +49 (69) 710 455 450 e: info.germany@ir.com
in linkedin.com/companies/integrated-research
For more information visit our website at www.ir.com
About Integrated Research (IR) - IR is a leading global provider of high-definition performance monitoring, diagnostics and reporting software. The creator of
award-winning Prognosis® and PowerMinder®− IR builds scalable, customizable solutions designed to manage continuity-critical IT infrastructure, payments
and communications ecosystems. IR provides real time solutions that give customers the insight they need to run their business, reduce their operating costs,
minimize risk, and gain competitive advantage.
© 2012 Integrated Research Limited. Prognosis is a registered trademark of Integrated Research Limited. All other brand and product names are trademarks or registered trademarks of their respective companies.
For more information visit our website at www.ir.com
About Integrated Research (IR) - IR is a leading global provider of high-definition performance monitoring, diagnostics and reporting software. The creator of award-winning
Prognosis® and PowerMinder®− IR builds scalable, customizable solutions designed to manage continuity-critical IT infrastructure, payments and communications ecosystems. IR
provides real time solutions that give customers the insight they need to run their business, reduce their operating costs, minimize risk, and gain competitive advantage.
© 2012 Integrated Research Limited. Prognosis is a registered trademark of Integrated Research Limited. All other brand and product names are trademarks or registered trademarks of their respective companies.
Contact us
Americas t: +1 (303) 390 8700 f: +1 (303) 390 8777 e: info.usa@ir.com
twitter.com/IRPrognosis
Asia Pacific/Middle East/Africa t: +61 (2) 9966 1066 f: +61 (2) 9966 1042 e: info.ap@ir.com
United Kingdom t: +44 (0) 1344 894 200 f: +44 (0) 1344 890 851 e: info.europe@ir.com facebook.com/IntegratedResearch
Germany t: +49 (69) 710 455 255 f: +49 (69) 710 455 450 e: info.germany@ir.com
in linkedin.com/companies/integrated-research
For more information visit our website at Prognosis.com/UC
UC0191-01
About Integrated Research (IR) - IR is a leading global provider of high-definition performance monitoring, diagnostics and reporting software. The creator of
award-winning Prognosis® and PowerMinder® − IR builds scalable, customizable solutions designed to manage continuity-critical IT infrastructure, payments
and communications ecosystems. IR provides real time solutions that give customers the insight they need to run their business, reduce their operating costs,
minimize risk, and gain competitive advantage.
© 2012 Integrated Research Limited. All rights reserved. Prognosis is a registered trademark of Integrated Research Limited. All other brand and product names are trademarks or registered trademarks of their respective companies.