Speech is an essential but frequently overlooked aspect of call quality in a contact center.
Speech is a specific subset of audio that captures how well an agent’s spoken voice translates into heard communication for the caller/customer.
There are several ways to measure speech quality, including spoken and automated voice, and measuring this helps extract the expected ROI from contact center investments.
A low speech quality score usually means there are severe technical issues impacting voice and sound relay across the communication lines.
Of course, this can influence the customer and agent experience. However, it may also affect the success of voice technologies, including speech analytics.
What Is Speech Quality?
Speech quality is a subjective measure of how well a listener/group of listeners can interpret human or synthetic speech and receive the intended information.
As the definition suggests, the concept has several traits:
- It Is Subjective – It’s impossible to assign an outright score to a piece of recorded or live speech. There must be a listener, with quality assessed in the context of the said listener.
- It Can Be Synthetic – Contact centers can assess the speech quality of IVRs and intelligent voice assistants, alongside that coming from customers and agents.
- It Is Influenced By Technology and the Environment – Alongside the agent's speech, the voice channel relays ambient noise from the surrounding environment, and microphone stutters that reduce speech quality.
Just remember, speech quality doesn't capture how clear the agent's voice was. Instead, it tries to measure the difference between the agent's speech in real life - i.e., as heard in the contact center - and what the customer hears - i.e., as heard after passing through the telephony system.
The Industry Standard for Measuring Speech Quality
There are many ways companies can test the voice quality offered by their phone technology. Perhaps the easiest solution is to ask someone to call a business contact number and evaluate the audio quality.
However, since factors like location and time can sometimes affect audio quality, this strategy could deliver limited insights.
Many leading contact center innovators currently have tools to help companies monitor, examine, and measure speech quality more accurately. These typically rely on an industry-standard audio quality measure known as PESQ or Perceptual Evaluation of Speech Quality.
PESQ is an International Telecommunication Union-approved standard for measuring audio quality. It examines everything from audio sharpness and call volume to background noise, variable latency, lag in audio, clipping, and audio interference.
Also, PESQ allows for audio quality testing on multiple types of calls, from mobile and fixed lines to toll-free and toll services, and across VoIP and PSTN networks.
