Interactive Voice Response (IVR) workflows allow you to send recorded voice messages to which your contacts can respond by using their keypad or recording their own message.
Voice workflows are handy for three reasons:
They allow you to send and receive voice messages that by nature allow for improved tone, character and length when compared with text messages.
They're synchronous - clients and beneficiaries are actively engaged with your workflow for the duration of the call.
They don't require that your contacts are literate, allowing you to reach communities with lesser access to education.
Voice flows are only available to accounts who've added voice-enabled Twilio or Vonage numbers. If neither Twilio or Vonage provide voice-enabled phone numbers in your country, you can use Twilio to add voice functionality to an Android channel.
To create a voice flow, navigate to the flows tab and click the 'Create Flow' box. At the bottom of the dialogue, adjust the Run flow over setting to Phone Call. Click 'Ok'.