Telephony
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.
00-12personto agent00-37voicemaildropped00-58virtual receptionistdropped00-74silencedroppedFeatures
What the platform detects
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
Dialed3 120of 24,000People1 044to agentBots612droppedRepeat612 numbersin the eveningAutomated messages without wasted minutes
Appointment and payment reminders go out without agents, but there's no point in playing the message to voicemail. The platform ends that call and schedules the number for the next attempt, while a customer who answered hears the full message. Automated reminder calls need the customer's prior consent.
- Message only to people
- No wasted minutes
- Retries by your rules
00-41voicemaildroppedMessagenot played0 minutesAttempt 2tomorrow 11:00 AMscheduled00-42personlisteningAI doesn't talk to a machine
If a voice AI consultant handles outbound calls, the check runs before its first word. It doesn't start a conversation with an answering machine or spend paid speech service minutes on someone's voicemail greeting.
- Check before the first word
- No paying for wasted speech
- Number goes back for a retry
Replyanswering machinedroppedReviewbefore anyone speaksdoneSpeech0 minutesnot billedRoomto retryafter 2 hoursIn 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
Speech start0.3 sright awayGreeting6 sno pauseAlertyesrecordingSummaryvoicemailhang upDecision
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
Personto an agent“Database” queueAI agenthang up, flagretrySilencehang up, flagretryUnsureto an agentper settingsTraining
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
Enrollmentfrom recordingsyour callsErrorsfrom agentsaddedComparisonvs. previousgeneric setSummarymore accurateonLaunch
How we set it up
- 01ReviewWe listen to recordings of past campaigns and calculate what share of answers come from machines and voicemail.
- 02TypesWe decide which automated answers to drop right away and which to pass along according to the campaign script.
- 03IntegrationWe build the check into the auto dialer and other phone services where outbound calls run without an agent.
- 04BalanceWe tune the detection sensitivity and the acceptable pause before an agent answers, so the person isn't left waiting.
- 05TestingWe run a pilot campaign and check dropped calls against their recordings to make sure no real person was cut off.
- 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 detection | Without detection | |
|---|---|---|
| Agent time | Talks only to customers | Listens to machine greetings |
| Carrier minutes | The call ends almost instantly | Run while the agent listens to a recording |
| Predictive dialing | Agents get only people | Some connections go to machines |
| Voice AI | Speaks only to a person | Wastes speech on voicemail |
| Retries | Machine – the number is dialed again | Number counted as done |
| Connect rate | Shows real contacts | Inflated 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
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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