Guest Blogs

8th August 2024

A Guide to Mean Opinion Score (MOS)

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In this blog, we summarise the key points from a recent article from David McGeough at Scorebuddy where he explored what Mean Opinion Score (MOS) is, what affects it, its impact on your contact centre and strategies to improve it.

Even though phones are now used for much more than calls, they remain a popular way for customers to reach out. Despite numerous omnichannel service options, 59% of customers still prefer phone calls for support.

Call quality is crucial for a positive customer experience, impacting satisfaction, loyalty, and retention. Evaluating your call centre’s MOS is an essential metric to understand its performance, affecting both customer and agent experiences.

Mean Opinion Score Explained: Definition and Insights

In the context of call centres, the Mean Opinion Score is a metric used to evaluate the quality of voice communication and overall customer service standards.

This assessment typically covers the performance of telephony systems and the quality of interactions between customers and agents.

MOS Rating Scale:

The Mean Opinion Score (MOS) uses a 1 to 5 scale to evaluate call quality:

5: Excellent
4: Good
3: Fair
2: Poor
1: Bad

Measuring MOS:

There are two primary methods for measuring MOS:

Subjective Testing: Human listeners evaluate sample calls and rate their quality. While it may provide accurate results, it’s often time-consuming and costly.
Objective Testing: Automated tools and algorithms can mimic human judgment to rate call quality, often using the G.711 codec. This codec has a top score of 4.4, with most VoIP calls usually scoring between 3.5 and 4.2.

Key Factors Influencing MOS

Call centre performance and Mean Opinion Score are influenced by various factors. Knowing these can help you make informed decisions to maintain high call quality. Additionally, you can use these factors in your predictive models to estimate MOS, though human review may still be needed for finer details.

Network Conditions:

Vital for VoIP systems.
Network issues can cause call disruptions, affecting clarity and consistency.
Strong network infrastructure is essential for high call quality.

Latency:

Refers to the delay in voice data transmission.
High latency disrupts conversation flow, lowering MOS.
Minimizing latency ensures smoother communication.

Packet Loss:

Voice data is sent in packets; lost packets lead to unclear, gap-filled conversations.
Caused by poor network connections or bandwidth issues.
Reducing packet loss improves call clarity.

Jitter:

Variation in packet travel times results in choppy audio.
High jitter degrades audio quality, making conversations difficult.
Controlling jitter is crucial for maintaining clear audio.

Codec:

The choice of audio codec affects call quality.
Codecs compress and decompress audio data with varying efficiency.
Selecting the right codec can significantly enhance call quality and MOS.

Understanding these factors helps in maintaining high call quality standards and making informed decisions to improve your contact centre’s performance.

Why Mean Opinion Score (MOS) Matters for Call Centres

The Mean Opinion Score provides valuable insights into call centre performance and quality. While not a comprehensive measure, it offers a solid understanding of call quality and operational effectiveness.

Impact on Key Metrics:

MOS directly reflects customer satisfaction (CSAT). Poor call quality often leads to customer frustration, which can result in lost business and a damaged brand reputation. Conversely, a high MOS suggests effective communication, improving customer experience and boosting loyalty and other service metrics.

Effect on Agent Performance:

MOS also affects agent efficiency. High call quality allows agents to resolve issues more effectively, enhancing their performance metrics.

In contrast, poor call quality can lead to repeated issues and misunderstandings, potentially demotivating agents and reducing their productivity.

Role in Quality Assurance:

Integrating MOS into your quality assurance (QA) process is crucial for identifying and fixing call quality problems.

By analyzing MOS data, you can quickly address system or network issues, helping to maintain high standards and ensuring satisfaction for both customers and agents.

6 Strategies to Enhance MOS in Your Call Centre

Achieving a high Mean Opinion Score is essential for a successful contact centre. An improved MOS can lead to greater customer satisfaction, increased agent performance, and better operational efficiency.

Here’s how to elevate your call centre’s MOS:

1. Upgrade Network Infrastructure

A strong network infrastructure is crucial for maintaining consistent call quality. Invest in high-quality routers, switches, and enough bandwidth to manage peak call volumes effectively. Regular network monitoring is also essential to identify and address issues such as latency, jitter, and packet loss.

2. Reduce Jitter and Packet Loss

To ensure clear calls, reduce network problems like jitter and packet loss. Use jitter buffers, error correction, and packet loss concealment to keep conversations smooth and uninterrupted.

3. Select Efficient Codecs

Use advanced codecs like G.722 or Opus for better audio quality and bandwidth efficiency. Avoid older codecs like G.711 that may impact call clarity.

4. Implement Quality of Service

Voice data is crucial, so prioritize it over other network traffic. Use methods like Type of Service or Differentiated Services to manage traffic based on importance.

5. Maintain VoIP Equipment

Keep your equipment up to date and ensure agents have the latest hardware and software. Regularly update software and firmware, use high-quality noise-cancelling headsets, and consider dedicated VoIP hardware for heavy traffic.

6. Train Agents Thoroughly

Well-trained agents improve customer experience. Teach them clear communication, active listening, and give regular feedback to help them stay sharp.

How MOS Affects Customer Satisfaction

Improving your Mean Opinion Score strengthens your call centre’s foundation. Clear, uninterrupted calls lead to a better customer experience, boosting both Customer Satisfaction (CSAT) and Net Promoter Score (NPS).

High MOS ensures quality interactions, which helps agents resolve issues faster, resulting in happier customers who leave positive reviews and recommend your company.

Combining MOS with customer satisfaction metrics gives a complete view of your call centre’s performance. This helps you identify areas for improvement and better enhance the customer experience.