ChannelsVoice

Voice onboarding

Are you ready for your AI Agent to start helping customers over the phone? This guide takes you through the steps to onboard your AI Agent so that it can start handling Voice conversations.

This feature may not be included with your organization’s subscription package. For more information, contact your Ada team.

Twilio and Your Voice AI Agent

Ada’s Voice AI Agent is powered by Twilio. In almost every deployment, Ada provisions and manages the necessary Twilio resources for you—no separate Twilio contract or configuration required.

Most Voice customers use Ada’s central Twilio account.

  • An Ada team member will provision and configure one or more of the following so your AI Agent can receive calls and send and receive SMS:
    • Twilio phone number
    • Twilio SIP domain
    • Twilio Application
  • Ada maintains the Twilio configuration, monitors usage, and absorbs the telephony costs.
  • When this setup is complete, go straight to Enable Voice in Multiple Languages to continue onboarding.

Bring-your-own Twilio account (optional)

If you must use your own Twilio project—for regional compliance or existing contracts—expand the steps below to prepare your:

  • Twilio phone number
  • Twilio SIP domain
  • Twilio Application
  1. Set up one or more phone numbers with Twilio, using one of the following options:
  2. Submit your organization’s toll-free phone number(s) to Twilio for verification.

    • If you are using a toll-free number with your AI Agent and you want to be able to send SMS messages from it during a phone conversation, you will need to submit a Toll-Free Message Verification request to Twilio. For more information, see Toll-Free Message Verification for US/Canada at Twilio’s Help Center.

    • If you are using a local number with your AI Agent and you want to be able to send SMS messages from it during a phone conversation, you will need to submit an A2P (Application to Person) 10DLC (10 digit long code) registration request to Twilio. For more information, see Programmable Messaging and A2P 10DLC at Twilio’s Help Center.

  3. (Optional) Set up a SIP domain with Twilio.

    4. Your AI Agent can also receive calls from your contact center infrastructure, transferred over the public internet using Session Initiation Protocol (SIP). To do this, you first need to create a SIP domain in Twilio.

    1. Add at least one IP Access Control List (ACL) or Credential List in Twilio

      2. An Access Control List (ACL) is a security measure that manages who can access your network resources by specifying allowed IP addresses. In SIP communications, using an ACL enhances security by ensuring only trusted traffic can reach your Twilio SIP domain, preventing unauthorized access.

      This procedure takes you through configuring an IP ACL in Twilio, so Twilio only accepts SIP traffic that originates from your specified IPs. You can also choose to configure credential lists instead, so it only accepts traffic from specific usernames and passwords. For more information, see Inbound - Sending SIP to Twilio at Twilio’s Help Center.

      1. Log into Twilio Console.
      2. In your Twilio account, go to Develop > Voice > Manage > IP access control lists, then click Create new Access Control List. The Create new Access Control List window opens.
      3. In the Create new Access Control List window, fill in the following fields:
        1. Under ACL Friendly Name, enter a descriptive name that represents the purpose of the list (e.g., My Contact Center Platform IP Address).
        2. Under IP Address Range Friendly Name, enter a name to help identify the IP Address range.
        3. Under CIDR Network Address and Range, enter the specific IP address range that should be allowed access.
      4. Click Create new ACL to save the list and close the window. Then, click Create new IP Address Range to add an additional IP range to the list. The Add IP Address Range window opens.
      5. Repeat the previous steps for adding an IP Address Range.
      6. Click Save.
    2. Create a new SIP domain.
      1. Go to Develop > Voice > Manage > SIP domains.
      2. Click the plus sign to create a new SIP domain.
      3. Create a SIP URI/domain name. This property allows you to specify a global unique SIP domain that is used to route SIP traffic from your infrastructure over the public internet to the correct server hosted by Twilio in the cloud. For more information on SIP domains, see SIP URI/domain names at Twilio’s Help Center.
      4. If you wish to manually connect to a specific geographic Edge Location that is closest to the location of your communications infrastructure, see Localized SIP URIs at Twilio’s Help Center. This can reduce latency and improve call audio quality.
      5. Under Voice Authentication, beside IP Access Control Lists, select both of the IP Access Control Lists you created.
      6. Under Secure Media, click the toggle so it says Enabled.
      7. Click Save.

After getting your phone number and/or SIP domain set up with Twilio, you can connect it with your AI Agent.

Connect your Twilio account with your Ada AI Agent

In your Twilio account, you need to obtain your account string identifier (SID), and create an API key to use with Ada.

  1. On the Ada dashboard, go to Channels > Voice, then go to the Configuration tab. Keep this page open as you go into your Twilio account to get your account details, so you can paste them in as you find them.
  2. In your Twilio console, in your account info, find your Account SID. Your Account SID is a unique identifier that acts like a username when you’re using Twilio’s API. For information on how to find it, see Auth Tokens and How to Change Them at Twilio’s Help Center.
  3. On the Ada dashboard, under Twilio Configuration, paste your Account SID into the Twilio Account SID field.
  4. In your Twilio console, create a new API key. Enter a name into the Friendly name field, set the Key Type to Main, and leave the other settings with their default values.

    5. For information on how to create an API key, see API Keys and How to Change Them at Twilio’s Help Center. When you create an API key, you get both a key and a secret. You can only view the secret once for security reasons, so make sure you save it in a safe place.

  5. On the Ada dashboard, under Twilio Configuration, paste the API key into the Twilio API Key SID field, and paste the secret into the Twilio API Key Secret field.
  6. Configure your AI Agent to use a phone number, a SIP domain, or a Twilio Application to receive phone calls. Your AI Agent can only use one of these methods to receive phone calls. Click a section to expand the full instructions.

    7. For more information on how you can configure your AI Agent with your contact center platform, see Integrate your voice AI Agent with your Contact Center as a Service (CCaaS) provider.

  1. Select Phone Number.
  2. Under Default phone number, enter your Twilio phone number. This is the phone number your AI Agent will use to receive phone calls.
  3. If required, you can add additional numbers if you want to use them to serve different audiences (e.g,. end users who want to speak in specific languages, or if your AI Agent serves multiple brands). To do this, click Add another phone number, add the number, and select a default language for it.
  4. Under Fallback phone number, enter a fallback number. Ada will route calls to this phone number in the case of system downtime that prevents your AI Agent from responding.
  5. If required, you can select Use a different phone number for SMS and enter a different phone number to send and receive SMS messages instead of your main phone number.
  6. Click Save.
  1. Select SIP domain.
  2. Enter a SIP domain. This should follow the format your-domain-name.sip.twilio.com and should be the global unique SIP domain that you previously created.

    3. If you haven’t created a SIP domain yet, entering and saving a SIP domain here will create the domain in your Twilio account. You will then need to configure at least one IP Access Control List or Credential List in Twilio to use with this SIP domain.

  3. If required, you can add additional SIP domains that you created in Twilio if you want to use them to serve different audiences (e.g,. end users who want to speak in specific languages, or if your AI Agent serves multiple brands). To do this, click Add another SIP domain, add the domain, and select a default language for it.
  4. Under Fallback SIP address, enter a fallback SIP address. Ada will route calls to this SIP address in the case of system downtime that prevents your AI Agent from responding.
  5. Under SMS phone number, enter your Twilio phone number, so your AI Agent can use it to send and receive SMS messages, and so you can use it when you’re testing your AI Agent.
  6. Click Save.
  1. Select Twilio Application. When you select this option, Ada prepares to create a new Ada Twilio Application which it uses to receive phone calls.
  2. Enter the phone numbers used to receive calls.
    • Under Phone numbers used to receive calls, enter each phone number that your end users might dial before the call is transferred to your Ada Twilio Application.
    • For each phone number that is used to receive calls, select the default language for it. When Ada receives a call that was made to that phone number, the AI Agent will default to the configured language.
    • If there are multiple different phone numbers that end users dial before the call is transferred to Ada (e.g. different phone numbers for different audiences, languages, or brands), click Add another phone number, enter the phone number, and select a default language for it.
    • Note: If Ada’s Twilio Application receives an inbound call on a phone number that isn’t listed here, the AI Agent defaults to English.
  3. Under Fallback phone number, enter a fallback phone number. Ada will route calls to this phone number if, for any reason, your AI Agent becomes unresponsive and cannot answer calls.
  4. Under SMS phone number, enter a phone number from your Twilio account. Your AI Agent will use this number to send and receive SMS messages, and you can also use it for testing outbound calls from Ada.
  5. Click Save.
    • Ada creates the Twilio Application in your Twilio account.
    • Once saved, the Twilio Application ID field appears. This is your Twilio App SID. Copy this value for use in your phone system or contact center platform.

You can configure additional settings to fine-tune your AI Agent’s behavior during phone calls, but we’ll cover those and what they mean in later topics.

Your usage of Voice is subject to both applicable privacy and phone communication laws, and Twilio’s policies. These may vary based on your location and industry. If you have any questions, please contact Ada.

Enable Voice in multiple languages

Your AI Agent can be enabled to speak multiple different languages over the phone. For more information on enabling languages, see About multilingual support.

The following languages are available for voice:

  • English
  • French
  • German
  • Italian
  • Spanish
  • Swedish
  • Dutch

If you enable any of the above languages in your AI Agent, that language will be available in both Messaging and Voice - you can’t have any of these languages only enabled for one or the other.

Choose regional dialects for your languages

Some of the languages available in Voice also have support for different regional dialects of those languages:

  • English
    • Australia
    • Canada
    • United Kingdom
    • United States
  • French
    • Canada
    • France
  • Spanish
    • Spain
    • United States

The dialect you choose narrows down which speaking voices will be available for that language. When you choose a dialect for your AI Agent, your AI Agent will automatically use the default speaking voice for that language and dialect. You can always go into your settings and choose a different voice for that dialect instead.

Here’s how you can change the dialects available for your AI Agent:

  1. On the Ada dashboard, go to Channels > Voice, then go to the Dialects tab.

  2. For each language that has dialects available, in the Dialect/region list, select an available dialect.

  3. Click Save. Your AI Agent immediately starts using the dialects you chose for all conversations in the corresponding languages, for both internal testing and for any live voice content in your AI Agent.

Understand how your AI Agent determines the end user’s language

By default, your AI Agent determines the language to use with your end user based on the language metavariable. There are a few ways you can set the value of this metavariable:

  • Set a default language for the phone number or SIP domain

    For each phone number or SIP domain that your AI Agent uses to receive phone calls, you will need to assign a default language. When a call is received using that phone number or SIP domain, the end user’s language metavariable will automatically be set to that language.

  • Let end users select from a menu of enabled languages

    You can choose to begin all of your AI Agent’s calls with a menu that allows end users to select one of your enabled languages. If you turn on this menu, your AI Agent will serve it to all end users before the Greeting, even if the number is associated with a specific language.

    1. On the Ada dashboard, go to Channels > Voice, then go to the Language selection tab.
    2. To turn on the menu, select the Let callers select their own language checkbox. Your AI Agent’s enabled languages appear.
    3. For each of your enabled languages:

      • Toggle the language On or Off to control whether it appears in the menu.

      • For languages you want to appear in the menu, drag them higher or lower in the list. Your AI Agent will automatically assign each language a number that the end user can dial into their dialpad to select.

    4. Click Save. Your language selection menu becomes available immediately for all callers.

  • Use the End Users API

    You can use the End Users API to update a user’s profile to set the language metavariable.

  • Send language information in the SIP header

    If you’re using a SIP domain for your AI Agent to receive phone calls, you can include the language value in the user-to-user header. This will override the default language that you configured for that SIP domain.

  • Send language information as a Twilio Parameter

    If you’re using a Twilio Application for your AI Agent to receive phone calls, you can include the language value as a parameter when transferring a call to the Application.

Choose a speaking voice for your AI Agent

Choosing a speaking voice for your AI Agent is an important part of your AI Agent’s branding. You can change your AI Agent’s voice at any time to better fit your AI Agent’s branding needs.

  1. On the Ada dashboard, go to Channels > Voice, then go to the Speaking voice tab.

  2. Under Speaking voice, select a voice for each language you have enabled in your AI Agent.

  3. Optionally, in the text field, you can type in a text sample, like a message from your AI Agent, so you can hear your AI Agent read out a specific piece of your AI Agent content. Then, you can click the Play button beside a selected voice to play the sample.

  4. Click Save. your AI Agent immediately starts using the voices you selected for both internal testing and for any live voice content in your AI Agent.

Configure how long an end user can be silent before your AI Agent hangs up

You can choose how much time your AI Agent will wait for a end user to speak before it reprompts the end user.

  1. On the Ada dashboard, go to Channels > Voice, then go to the Configuration tab.

  2. Under Maximum caller silence (seconds), enter the number of seconds you want your AI Agent to wait before re-prompting the end user. After re-prompting the end user, the AI Agent will wait an additional 10 seconds before then ending the call.

  3. Click Save.

Improve recognition of special terms by adding them to your AI Agent vocabulary

If your business uses brand-specific product names, internal acronyms, or industry jargon that typical speech models might mishear, you can “teach” your Voice AI Agent to recognize them more reliably. By adding a short list of priority terms, the underlying speech-to-text engine will give extra weight to those words and phrases whenever it transcribes a call.

What makes a good priority term?

✅ Do include🚫 Avoid
Brand names, product SKUs, internal feature namesEveryday words the model already understands (“account”, “support”)
Industry-specific jargon and acronymsFull sentences or long paragraphs
Multi-word phrases up to ~4 words (e.g., “Flex-Plus warranty”)Terms with punctuation the end user won’t say aloud

This feature is currently only supported in English. If you have additional languages enabled in your AI Agent, adding terms to your vocabulary won’t affect how your AI Agent interprets those terms in those languages.

You usually need no more than 20–30 high-value terms to see a noticeable boost. We recommend against adding more than 50 terms. If you have too many terms, there is a risk that some of these may not be included.

  1. On the Ada dashboard, go to Channels > Voice, then go to the Vocabulary tab.

  2. Add, remove, or dig deeper into the terms in your list as required:

    • To add a new term, click New Term. A new row in your vocabulary table appears. Type in a term, then click Add term.

    • To delete an existing term, hover over its row and click the Delete button that appears.

    • To view all the conversations where end users used a term, beside that term, click View conversations.

By curating this vocabulary, you give the Voice AI Agent the context it needs to understand your end users accurately—leading to smoother conversations and better outcomes for everyone.

Have any questions? Contact your Ada team, or email us at .