Manager/Analyst > Configure your One-to-One service > Voicemail Detection

Voicemail Detection

Voicemail detection or Automatic Message Detection (AMD for short) is one of our latest features. It requires very little configuration and it is easily enabled. Nonetheless, there are a few things to keep in mind when using this feature. The purpose of Voicemail Detection is to improve the agents’ effectiveness by skipping calls answered by machines. The time saved by skipping those calls can be used on calls with real customers.

There is no standard to signal an outbound call as voicemail when the connection is established. AMD is done by listening to the audio input on the user side (the call we want to identify as human or machine). The system is silent during the time that it needs to listen. To mitigate the impact on the user’s experience (a delay with no response from the agent) the system has limited time to determine whether the call is being picked up by a human or machine.

Our Servers are currently using two communication systems to make and receive calls: the Twilio platform and the Asterisk framework. They both provide with AMD functionalities that we use to detect voicemail.

With AMD the agent will no longer receive calls and listen to a voicemail on the other end. The experience with AMD enabled will be slightly different in the case of LDS and Non-LDS Widgets.

Agent’s experience in LDS Widgets.

For an agent receiving a request on an LDS widget, the result of a call being detected as voicemail is the following:

Once the agent has clicked on the notification, the system will call the client. The AMD feature will evaluate the call to determine whether a customer´s voicemail has been reached or not. If the system detects a human, the agent will receive a call and the connection will be bridged between user and agent. This is the current behaviour for LDS.

In case the system detects a voicemail, the agent will be prompted with a message notifying of a connection failure. The agent is asked to End or Postpone the lead.

This is the same flow that we currently have with any other connection failure.

Agent’s experience in Non-LDS Widgets.

When the system detects a person, the call connects as expected, when reaching a voicemail, Whisbi´s AMD system will not connect the call and instead will automatically schedule a call back (this is the default behaviour, this can be configured, please speak to your CSM about this).

How to enable the AMD feature

To enable the feature, please contact your Customer Success Manager to discuss the activation of the Voicemail Detection. The feature can be enabled for a particular Widget and remain disabled on the rest of Widgets on the same Account.

For Non-LDS Widgets, there is also the possibility to configure the automatic transition of the request.

  • Account (e.g.: Whisbi Non-LDS voicemail Test Account): the account we want to configure.
  • Nextaction (default: Automatic call back): the next action to be executed when a call is detected as voicemail.
  • Time to next action (default: 1h 30m): the wait time for the next action to be executed.

If you wish to have different values configured, please, contact our Customer Success representatives.

This is all that needs to be done to have Voicemail Detection enabled for a given Widget.

Suggestions to measure the accuracy of your voicemail detection

To keep track of the feature’s accuracy, an observation of its results is very recommended. The accuracy can be calculated with the following formula:

AD = calls ended manually by agents as voicemail

CC = Total connected calls

Voicemail Detection Accuracy(%) = (1 – (AD/CC))%


  • AD are the voicemail answers that were incorrectly detected as human. These calls are considered false negatives.
  • CC includes the calls that were correctly detected as human and the false negatives.

Important: false positives (human answers incorrectly detected as machine) are not possible to detect, except by making calls ourselves and observing the result. For that reason they are not part of the formula.

To discover more information click here

There are a few known issues that can lead to false positives or false negatives when attempting to detect voicemail. The most common issues that we might find are:

  • The voicemail is not a long string of words or includes a pause, confusing the system into thinking it’s a live caller (also known as a false negative)
  • There is a small delay while the system connects the call to an agent, which could result in the receiver of the call possibly hanging up
  • The system incorrectly guesses a live call as a voicemail and hangs up (also known as a false positive)

To discover more information click here