Using Software Based Answer Detection

Software based answer detection provides a means of detecting when an outbound call has been answered in situations when this feature is not provided by the hardware.

Software based answer detection works by listening for an answer after a call has been dialed. The answer detection algorithm is not 100% accurate, but it has been designed to not recognize rings or busy signals as answered phone calls. Once an answer has been detected, the Call Tree begins processing. Software based answer detection may not work well in your region or with your hardware. If high quality answer detection is a requirement, consider Brooktrout telephony cards which provide their own answer detection features.

More information about software based answer detection and associated settings can be found in the section on Voice Telephony Settings.

Enable Software-Based Answer Detection

To enable answer detection:

From the menu bar, choose Tools ... Voice Telephony Settings. A dialog box will appear.

Click the Outbound Calls tab.

Check the box marked Use software based call answer detection.

Click Accept Settings to close the dialog box.

Customize Software-Based Answer Detection

There are two settings that can be customized for software based answer detection:

1. The volume tolerance: This setting determines how loud an answer must be in order to qualify as something besides line noise. Since different hardware devices have different audio input levels, experimenting with this setting could improve performance with different types of hardware.
2. The time-out setting: As humans, when we make phone calls we do not wait for an infinite amount of time for someone to answer. Usually, if someone hasn't answered our phone call within 20-30 seconds, we hang up. The time-out setting tells Active Call Center how long to wait for an answer before hanging up.

To change the volume tolerance or time-out settings:

Make sure software-based answer detection is enabled as described above.

From the menu bar, choose Tools ... Voice Telephony Settings. A dialog box will appear.

Click the Answer Detection tab.

Adjust the Volume Tolerance or Number of settings before assuming no answer using the appropriate up/down arrows.

Click Accept Settings to close the dialog box.

Differences in Prompt Design for Answer Detection

Call Trees that are designed to work without answer detection should have initial prompts that repeat many times. This is to guarantee that the prompt is playing whenever the other party answers the call. To see an example of this, examine the prompts in the Answer_Phone Node of the Outbound Call Survey Call Tree in the Examples folder.

Call Trees designed to work with answer detection do not need a repeating prompt. Here, the assumption is that the Call Tree will only start after the other party has answered. Therefore, a prompt is virtually guaranteed to be heard by the dialed party and should not be repeated many times.

Adding Delays to Improve Software Based Answer Detection

On some modems and phone systems there are clicks or pops immediately after dialing that may be mistaken for an answered line. Some of these problems can be alleviated by adding an extra comma (",") at the end of the number. A comma adds a pause at the end of the number before switching control to Active Call Center, thereby bypassing the clicking and popping noises.