The DTMF Response - Voice node enables an AI Agent to collect caller input during voice conversations using keypad entries, spoken responses, or both.

DTMF (Dual-Tone Multi-Frequency) signals are generated when a caller presses keys on a telephone keypad. Use this node when callers need to select menu options, enter numeric values, or provide information that is more reliably captured through keypad input than speech.

Depending on the configuration, callers can:

• Press 1 to check an order status.
• Press 2 to speak with support.
• Enter a 10-digit mobile number.
• Enter an order ID followed by the # key.
• Provide an OTP or verification code.

The node captures the response, validates the input, and routes the conversation to the appropriate next step.

Prerequisites

Before adding a DTMF node, ensure that:

• Enable Voice was selected when the application was created.
• A language is configured in the Dialogue Tree settings.
• A valid voice configuration is available for the AI Agent.
• The dialogue flow includes paths for valid responses, invalid responses, timeouts, and fallback handling.

When to Use the DTMF Node

Menu-Based Navigation

Use keypad selections to route callers to different conversation paths.

Example prompt

Press 1 for order status. Press 2 to speak with customer support.

The AI Agent routes the caller based on the selected digit.

Fixed-Length Numeric Input

Collect a predefined number of digits, such as:

• Mobile numbers
• Account numbers
• Verification codes
• OTPs

Example prompt

Please enter your 10-digit registered mobile number.

The AI Agent waits until the configured number of digits is entered before proceeding.

Variable-Length Input

Collect values whose length can vary.

Common examples include:

• Order IDs
• Customer IDs
• Reference numbers

Example prompt

Please enter your order ID followed by the hash key.

The AI Agent captures input until the configured end key is pressed.

Sensitive Data Collection

Use the node to securely collect sensitive information when the required data protection configuration is available.

Examples include:

• Card numbers
• CVV values
• Card PINs
• OTPs
• Identification numbers
• Dates of birth

Add a DTMF Node

Add the DTMF node at the point in the conversation where caller input is required.

Steps

1. Open Tasks.
2. Click the arrow next to + Add Task and select Create Dialogue Tree.
3. Enter a task name and description.
4. Click Save.
5. In the Dialogue Tree Builder, click + and select DTMF Response - Voice.

Configure the DTMF Node

Basic Configuration

Enter the following details:

• Name: Enter a node name.
• Languages: Select supported languages.

Response Type

Select how callers can provide responses.

Recommendations

• Use DTMF for menu selections and numeric input.
• Use DTMF and Speech when callers should be able to choose between speaking and pressing keys.

Number of Input Digits

Specify how many digits the caller must enter.

After the specified number of digits is received, the AI Agent processes the input and continues the conversation.

Configure Valid Digits

When Number of Input Digits is set to 1, configure the accepted keypad values.

Example

Prompt:

Press 1 for Returns. Press 2 for Support.

Valid digits:

• 1
• 2

Create an output path for each configured digit.

Configure Input Variables

For inputs longer than one digit, use an input variable instead of valid digits.

The entered value is stored and can be used later in the flow.

Example

orderIdmobileNumbercustomerIdotpValue

The stored value can be used to:

• Call an API.
• Retrieve order details.
• Validate user input.
• Confirm information back to the caller.

Variable Naming Guidelines

Variable names:

• Must not start with a number.
• Must not start with a special character.
• Must not contain spaces.

Valid examples:

orderIdmobileNumbercustomerIdotpValue

Speech Input Settings

Configure these settings when Speech or DTMF and Speech is selected.

Configure the Prompt

Use Operator Says to define the message played before input is collected.

The prompt should clearly explain:

• What information is required.
• Whether the caller should speak or press a key.
• Available options.
• Whether an end key is required.

Example Prompts

Press 1 to check your order status. Press 2 to speak with support.

Please enter your order ID followed by the hash key.

Please enter your 10-digit registered mobile number.

Additional Settings

Enable Recording

Record caller interactions at this node for:

• Quality monitoring
• Auditing
• Troubleshooting

Sensitive Data

Enable this option when collecting protected customer information.

PCI Data

Use when collecting payment-related information such as:

• Credit card numbers
• Debit card numbers
• CVV
• Card PIN
• OTP

PCI data is securely processed through the configured Cardholder Data Environment (CDE).

PII Data

Use when collecting personally identifiable information such as:

• Date of birth
• Government identification numbers
• Social Security numbers

PII values are masked in the user interface while remaining available to backend systems according to configured data-handling policies.

Wait for End of Prompt

Enable this option to prevent callers from entering input while the prompt is still playing.

Input is accepted only after the prompt finishes.

Timeout

Specify how long the AI Agent should wait for a response.

If no response is received within the configured duration, the timeout path is triggered.

End Key

Specify the key that indicates input completion for variable-length values.

Retry Count

Specify how many times the AI Agent should repeat the prompt when no valid response is received.

For example, a value of 2 causes the prompt to play once initially and repeat up to two additional times.

Configure Next Paths

Configure routing for:

• Valid keypad input
• Valid multi-digit input
• Valid speech input
• Invalid input
• Timeout
• Default fallback path

Example Menu

Prompt:

Press 1 for order status. Press 2 for customer support.

Configure the following paths:

After configuration, connect each output path to the appropriate node, such as a bot response, API call, agent handoff, or conversation end node.

Example: Order Status Menu

Output Paths

• 1 → Order Status
• 2 → Customer Support
• Invalid Input → Retry message
• Timeout → Timeout message
• Default Path → End call or transfer to support