Call Progress Detection

We have written various articles regarding this topic. This one is updated to reflect changes in the user interface and specifically to address the cloud solution.

What is Call Progress Detection

The key to any automated dialer system or software is the ability to tell whether a call is answered by a live human or a machine. For predictive dialer, live answers are transferred immediately to agents and machine answered are either skipped or a voice mail message left after the beep. Unfortunately, there is no standard signal or indicator from the telephone service that dialer can use for this purpose.

The process to detect live answer vs. machine answer is called call progress detection. It basically analyzes the initial phone audio and makes a decision based on some criteria. Earlier dialers use some simple and not so smart detection algorithms, largely because computers are not that fast to analyze the data in real time, some systems use hardware for this purpose. Modern dialers like Voicent dialers, mostly use software algorithm for detection.

Can Detection Algorithm Achieve 100% Accuracy?

No. Technically it is impossible to achieve 100% accuracy because the lack of standard signal and the detection must be made in the first few seconds in real time. In addition, the way people answer the phone, the timing, and way people’s machine messages are all different. No system today (probably in the future) can be 100% accurate. The best system for prediction is probably the human perception system. But even humans make mistakes from time to time.

Just imaging you make a call and you can only hear the audio in the first second. You may hear someone says “hello” and the audio cut off. By just analyzing this short audio clip alone, it is not easy to tell whether it is a live answer or a machine message starts with hello. Obviously the algorithm needs to take other things into consideration to make a better decision, but the difficulty remains.

When the detection algorithm makes a mistake, it can cause problems like these: there is a delay before the audio message is played; the system does not leave a message on answering machine; the message on answering machine is being cutoff; no popup screen for live answer for some predictive calls; machine answer is connected to agent.

We believe Voicent have the best algorithm

Voicent has spent a lot of development time to improve the accuracy. Our detection algorithm is based on intelligently analyzing the incoming audio and apply the best fit statistical patterns based on a large amount of data collected. Since our products has been on the market for more than fifteen years, Voicent software is battle tested in real world and the accuracy is second to none.

You Can Control the Algorithm

The longer the software analyzes the audio (delay), the more accurate it gets. So if you can tolerate more machines be treated as live answer (agents can just hang up the call), you can shorten the delay. In special situations (such as only calling businesses), you can turn off the detection algorithm – no delays but all calls are treated as live answer. To control the settings, go to Setup, Account, Call Control page.

Balanced Default settings. Recommended for general usage.
More Aggressive Use less time to detect. More machine answer will be treated as live answer.
Most Aggressive Use least time to detect. Almost all machine answer will be treated as live answer.
No Detection No time to detect. Treat every call as live answer as soon as the call is answered.

Recommendations for Agents

When a detection is made, the system connects the call to agent right away. The connection is happening in computer time, which means it does not create discernible delay unless the computer is really slow and the network has some extra delays. Below are some recommendations for agents:

• Try to talk as soon as audio is established. Do not wait for the whole CRM page is displayed.
• Do not run other software in the background, especially those use audio.
• do not use a wireless headset, use a USB based one.
• When your computer gets sluggish, reboot.