Create answer-machine-detection.md

implement answer machine detection documentation

Author: valindrae

articles/communication-services/concepts/call-automation/answer-machine-detection.md

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+---
+title: Building Answer Machine Detection
+titleSuffix: An Azure Communication Services concept document
+description: Learn how to 
+author: Kunaal
+ms.service: azure-communication-services
+ms.subservice: call-automation
+ms.topic: conceptual
+ms.date: 03/07/2025
+ms.author: kpunjabi
+ms.custom: public_preview
+---
+
+# Implementing Answer Machine Detection with Call Automation
+
+Answer Machine Detection (AMD) helps contact centers identify whether a call is answered by a human or an answering machine. This guide will show you how to implement a simple AMD solution using Dual-Tone Multi-Frequency (DTMF) tones with Azure Communication Services existing play and recognize APIs.
+
+To achieve this developers can implement a logic that uses the call connected event and plays an automated message requesting the callee to press a specific key verifying that they are a human before connecting them to an agent or playing a more specific message. 
+
+## Step-by-step guide 
+1. Create an outbound call. If you're not familiar with creating outbound calls you can review our [quickstart](../../quickstarts/call-automation/quickstart-make-an-outbound-call.md).
+2. Once the call is answered you will get a `CallConnected` event. This lets your application know that the call has been answered, at this stage it could be a human or an answer machine.
+3. After receiving the `CallConnected` event your application should use the [recognize API](./recognize-action.md) and play a message to the callee requesting them to press a number on their dial pad to validate they're human, for example your application might say "This is a call from [your company name] regarding [reason for call]. Please press 1 to be connected to an agent."
+4. If the user presses a key on the dialpad, Azure Communication Services will send a `RecognizeCompleted` event to your application. This indicates that a human has answered the call and you should continue with your regular workflow.
+5. If no DTMF input is received, Azure Communication Services will send a `RecognizeFailed` event to your application. This indicates that this call has gone to voicemail and you should follow your voicemail flow for this call.
+
+## Example code 
+
+```csharp
+//... rest of your code
+
+var ttsMessage = "This is a call from [your company name] regarding [reason for call]. Please press 1 to be connected to an agent.";
+var playSource = new TextSource(ttsMessage)
+{
+    PlaySourceId = "playSourceId"
+};
+
+var playOptions = new PlayOptions
+{
+    Loop = false
+};
+
+callConnection.Play(playSource, playOptions);
+
+var recognizeOptions = new RecognizeOptions(new DtmfOptions(new[] { DtmfTone.One }))
+{
+    InterruptPrompt = false,
+    InitialSilenceTimeout = TimeSpan.FromSeconds(5),
+    PlayPrompt = playSource
+};
+
+var recognizeResult = callConnection.Recognize(recognizeOptions);
+
+// Handle the recognition result
+if (recognizeResult.Status == RecognizeResultStatus.Recognized && recognizeResult.RecognizedTone == DtmfTone.One)
+{
+    // Connect the call to an agent
+    Console.WriteLine("Human detected. Connecting to an agent...");
+    // Add your logic to connect the call to an agent
+}
+else
+{
+    // Classify the call as an answering machine
+    Console.WriteLine("No response detected. Classifying as an answering machine...");
+    // Add your logic to handle answering machine
+}
+
+//... rest of your code
+```
+
+## Next steps
+- Learn more about [Call Automation](../../concepts/call-automation/call-automation.md) and its features. 
+- Learn more about [Play action](../../concepts/call-automation/play-action.md).
+- Learn more about [Recognize action](../../concepts/call-automation/recognize-action.md).