Empathic Voice Interface | Sample Flutter App

This project features a sample implementation of Hume's Empathic Voice Interface using Flutter. This is lightly adapted from the stater project provided by flutter create.

Targets: The example supports iOS, Android, and Web.

Dependencies: It uses the record Flutter package for audio recording, and audioplayers package for playback.

Instructions

1. flutter pub get to install dependencies.

2. Copy the .env.example included in the repository to .env and fill in HUME_API_KEY and HUME_CONFIG_ID appropriately, see our documentation on getting your api keys.

   Note: the HUME_API_KEY environment variable is for development only. In a production flutter app you should avoid building your api key into the app -- the client should fetch an access token from an endpoint on your server. You should supply the MY_SERVER_AUTH_URL environment variable and uncomment the call to fetchAccessToken in lib/main.dart.

3. Use flutter run to start the app!

4. If you are using the Android emulator, make sure to send audio to the emulator from the host.

Notes

• Echo cancellation. Echo cancellation is important for a good user experience using EVI. Without echo cancellation, EVI will detect its own speech as user interruptions, and will cut itself off and become incoherent. This flutter example requests echo cancellation from the browser or the device's operating system, but echo cancellation is hardware-dependent and may not be provided in all environments.
  • Echo cancellation works consistently on physical iOS devices and on the web.
  • Echo cancellation works on some physical Android devices.
  • Echo cancellation doesn't seem to work using the iOS simulator or Android Emulator when forwarding audio from the host.
  • If you need to test using a simulator or emulator, or in an environment where echo cancellation is not provided, use headphones, or enable the mute button while EVI is speaking.