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Answering machine detection

CONTACT.WORK answering machine detection listens to the start of every outbound call and determines whether a person picked up. If so, the call goes to an agent. Voicemail, carrier messages like "the number you have dialed is not available", virtual receptionists, and silence are dropped and flagged in the campaign report. Over time, the model is retrained on your company's calls, and you tune how strict the check is to match your goal: never miss a customer or never waste agent time.

>80%of answering machinesdetected
≈80%of silent callsidentified correctly
4types of machine answersplus silence
3implementation stagesincluding model training

Features

What the platform detects

VoicemailRecognizes the voicemail greeting and the beep before recording.
Carrier messagesRecognizes "the number is not available" and other prerecorded carrier messages.
Receptionists and assistantsDoesn't mistake a virtual receptionist or a voice assistant for a person.
Dead airTells silence after the answer apart from a short pause by the person on the line.
Detection sensitivityMake the check looser for high-value leads and stricter for a large list.
Report flagsEvery dropped call is flagged: voicemail, carrier message, receptionist, or silence.

Examples

Where to turn detection on

Three kinds of outbound calls where machines waste the most time.

Calling a large list

Your sales team calls thousands of numbers, and a noticeable share of answers come from machines. Detection drops them before the call is connected, so predictive dialing doesn't hand agents someone's voicemail greeting. Numbers that reached a machine are dialed again later.

  • Screened before connecting
  • Another attempt later
  • No idle agents
Example 1 of 3

In all three cases, a number that reached a machine isn't lost – it gets dialed again.

How it works

How detection works

Analysis

What the platform listens for

After the call is answered, the platform analyzes the audio: how soon speech starts, how long the greeting lasts, whether the other side waits for a reply, and whether there's a recording beep. The machine learning model also takes the voice itself into account – that's how it recognizes assistants that greet you almost like a person.

  • Speech start and pauses
  • Greeting length
  • Voice and recording beep

Decision

After the check

If a person answered, they're connected right away to whoever the campaign assigned. If a machine answered or there's silence on the line, the call ends and gets flagged, and the number is dialed again under your retry rules – or, for voicemail, you can leave a recorded message instead. If the platform isn't sure, it does what you've configured: connect or drop.

  • Person – to an agent
  • Machine – flag and retry
  • Unsure – per your settings

Training

How the model gets more accurate

Outbound call recordings are automatically collected into a training set. If an answering machine does reach an agent, the agent flags the error with one click, and that call goes into the set too. A new model version is compared with the previous one on a shared set of calls and goes live only if it's more accurate.

  • A training set from your recordings
  • One-click error reporting
  • Each version beats the last
No shifts wasted on machinesPaid agent time goes to customers, not recordings.
Fewer carrier minutesA call to a machine ends within seconds, so it uses fewer minutes.
More conversationsWith the same contact list, each agent talks to more people per shift.
A real connect rateThe report counts live answers, not just picked-up calls.

Launch

How we set it up

  1. 01ReviewWe listen to recordings of past campaigns and calculate what share of answers come from machines and voicemail.
  2. 02TypesWe decide which automated answers to drop right away and which to pass along according to the campaign script.
  3. 03IntegrationWe build the check into the auto dialer and other phone services where outbound calls run without an agent.
  4. 04BalanceWe tune the detection sensitivity and the acceptable pause before an agent answers, so the person isn't left waiting.
  5. 05TestingWe run a pilot campaign and check dropped calls against their recordings to make sure no real person was cut off.
  6. 06TrainingWe retrain the model on the collected recordings and track accuracy regularly, especially after a script change.

Economics

Outbound calling with and without detection

With detectionWithout detection
Agent timeTalks only to customersListens to machine greetings
Carrier minutesThe call ends almost instantlyRun while the agent listens to a recording
Predictive dialingAgents get only peopleSome connections go to machines
Voice AISpeaks only to a personWastes speech on voicemail
RetriesMachine – the number is dialed againNumber counted as done
Connect rateShows real contactsInflated by answering machines

Requirements

What you'll need

Telephony
Asterisk – in our cloud or your own
Dialing
Our auto dialer or yours, via API
Connectivity
Any SIP carriers and destinations
Recordings
Past campaigns – to train the model
Reports
By campaign, answer type, and carrier
Price
No licenses; work is billed in support hours

Preparation

What to decide up front

Which answers to drop?Voicemail, carrier messages, receptionists, assistants, and silence – or some of them.
What matters more for the campaign?Not missing a single person, or saving agent time on a large list.
What to do with a machine's number?Leave a voicemail message, retry later, or remove the number from the campaign.
What pause is acceptable?How many seconds the customer will wait while the check runs before an agent picks up.
Where to test the settings?A pilot run on a small sample of numbers, plus listening to dropped calls.
What's your call volume?How many numbers a day and how many outbound agents – that's what determines the payoff.

Q&A

Frequently asked questions

What share of answering machines does detection catch?

More than 80% on average. Accuracy depends on the region and the carrier: each has its own prerecorded messages and voice assistants.

How does the platform handle silence on the line?

About 80% of calls with silence after the answer are identified correctly. Accuracy improves as the model is updated under your support plan.

Could the platform drop a real person?

Any detection system carries that risk, so the check is tuned for each campaign. Where a customer is especially valuable, it's loosened: better for an agent to hear an extra answering machine than to lose a person.

How much longer does the customer wait for an agent?

The check takes the first few seconds after the answer. We tune the acceptable pause during setup – it's a balance between accuracy and the customer's wait.

Does the platform recognize assistants that sound like people?

Besides pauses and greeting length, the model takes the voice into account. It tells virtual receptionists and voice assistants apart from a human on the line.

What happens to the number if a machine answered?

The call ends with a flag, and the number goes into the campaign's next attempt – for example, at a different time of day.

Can I leave a message on voicemail?

Instead of dropping the call, the platform can wait for the beep and play your message – for example, a request to call back or an appointment reminder. Under the TCPA, prerecorded messages generally require the person's prior consent, so use this only for contacts who agreed to it.

Can I check whether a call was dropped correctly?

Dropped calls are flagged in the report and recorded, and you spot-check them by listening during setup and after launch.

How does the model learn from our recordings?

Outbound call recordings automatically build up as training examples, along with errors flagged by agents. The model is retrained and tested on your calls before it goes live.

Does it work with our own auto dialer?

It does. Through the API, your system learns who answered the call and then applies its own rules.

Does the platform check answers when calling customers back?

When the platform calls back someone whose call was missed, an answering machine won't reach an agent, and the attempt is repeated under your callback rules.

Which languages does detection work in?

English is supported: the model recognizes English-language voicemail greetings and carrier messages, and it also checks calls to international numbers. A pilot campaign shows the accuracy on your list.

Do I need detection if each agent gets one call at a time?

When the platform dials one number per available agent, the agent is connected as soon as someone picks up – without detection, they'd be listening to answering machines themselves. With detection, only people get through.

Can detection run on our own server?

It can. Detection is installed along with the other modules – in our data center or on your premises.

How do I calculate the payoff from detection?

Take the number of outbound calls per day, the share of machine answers from the report, and the average time it takes an agent to recognize a machine by ear. Multiply them to get the agent hours you're currently wasting, then add the carrier minutes spent on those same calls. A pilot campaign will show these numbers on your own list.

How much does detection cost?

There are no licenses. Our own model detects answering machines on the server, so there's no per-minute speech recognition fee. Setup, configuration, and model training are billed in support hours, and carrier minutes are paid to your carrier.

Glossary

Terms on this page

Voicemail
A recorded message when the person does not pick up. Learn more →
Answering machine detection (AMD)
Tells whether a person or an answering machine picked up an outbound call. Learn more →
Predictive dialer
The system dials numbers in advance, predicting when an agent will be free. Learn more →
Call recording
Calls are saved so they can be replayed and disputes settled. Learn more →
API (application programming interface)
The way programs exchange data with each other without a person in the loop. Learn more →
Callback
The customer doesn't wait on hold but asks for a callback – and gets one when an agent is free. Learn more →
Cloud deployment (cloud)
The platform runs on the vendor's servers, and agents connect over the internet. Learn more →
SIP (Session Initiation Protocol)
The protocol that sets up calls in IP telephony. Learn more →
Automatic callback
The system calls back everyone who couldn't get through. Learn more →
Data center
A building with servers, backup power, cooling, and network links. Learn more →
Speech-to-text
Turns spoken conversation into text. Learn more →

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