DEV Community

vmodal_ai
vmodal_ai

Posted on

Implementing Voice Commands in Google Glass Android Apps with Kotlin

#android #androiddev #voicecommand #development

Voice commands are one of the most powerful features of Google Glass and other Android-based smart glasses. Instead of relying on touch input, users can control applications using natural speech, making hands-free interaction ideal for healthcare, logistics, manufacturing, and field services.

In this tutorial, you'll learn how to add voice recognition to your Google Glass Android application using Kotlin.

Why Use Voice Commands?

Voice interaction improves both usability and productivity by allowing users to:

  • Navigate screens hands-free
  • Start workflows instantly
  • Capture information while working
  • Improve safety in industrial environments
  • Reduce manual interactions

Prerequisites

Before you begin, ensure you have:

  • Android Studio
  • Basic Kotlin knowledge
  • A Google Glass or Android-based smart glasses device
  • Android SDK installed

Step 1: Add Audio Permission

Open AndroidManifest.xml and request microphone access.

<uses-permission android:name="android.permission.RECORD_AUDIO"/>
Enter fullscreen mode Exit fullscreen mode

You'll also need to request this permission at runtime on Android 6.0 and later.

Step 2: Launch Voice Recognition

Android provides a built-in speech recognition intent.

private fun startVoiceRecognition() {
    val intent = Intent(RecognizerIntent.ACTION_RECOGNIZE_SPEECH)

    intent.putExtra(
        RecognizerIntent.EXTRA_LANGUAGE_MODEL,
        RecognizerIntent.LANGUAGE_MODEL_FREE_FORM
    )

    intent.putExtra(
        RecognizerIntent.EXTRA_PROMPT,
        "Say a command"
    )

    startActivityForResult(intent, 100)
}
Enter fullscreen mode Exit fullscreen mode

This opens the Android speech recognition interface and listens for spoken input.

Step 3: Receive Voice Commands

Handle the recognition result inside your activity.

override fun onActivityResult(
    requestCode: Int,
    resultCode: Int,
    data: Intent?
) {
    super.onActivityResult(requestCode, resultCode, data)

    if (requestCode == 100 && resultCode == RESULT_OK) {

        val results = data?.getStringArrayListExtra(
            RecognizerIntent.EXTRA_RESULTS
        )

        val command = results?.firstOrNull()

        command?.let {
            processCommand(it)
        }
    }
}
Enter fullscreen mode Exit fullscreen mode


The recognized speech is returned as text, which you can process in your application.

Step 4: Execute Commands

Create a simple command handler.

private fun processCommand(command: String) {

    when (command.lowercase()) {

        "start" -> {
            // Start workflow
        }

        "camera" -> {
            // Open camera
        }

        "next" -> {
            // Next step
        }

        "finish" -> {
            // Complete task
        }

        else -> {
            // Unknown command
        }
    }
}
Enter fullscreen mode Exit fullscreen mode

You can extend this logic to support dozens of custom voice commands.

Best Practices

To create a reliable hands-free experience:

  • Keep commands short and easy to pronounce.
  • Avoid similar-sounding command phrases.
  • Provide clear visual feedback after recognition.
  • Handle unrecognized speech gracefully.
  • Support offline functionality whenever possible.

Common Enterprise Use Cases

Voice commands are widely used in Google Glass applications for:

  • Warehouse picking
  • Equipment inspections
  • Medical documentation
  • Field technician workflows
  • Navigation between work instructions
  • Remote assistance

Tips for Better Performance

For the best user experience:

  • Minimize background processing while listening.
  • Test in noisy environments.
  • Cache frequently used data.
  • Keep UI updates lightweight.
  • Optimize battery consumption during long sessions.

Conclusion

Adding voice commands to a Google Glass Android app is straightforward thanks to Android's built-in speech recognition APIs. By combining Kotlin with Android's voice capabilities, you can build intuitive, hands-free applications that improve productivity and safety across enterprise environments.

As your application grows, consider integrating on-device speech recognition, natural language processing, or AI assistants to create even smarter wearable experiences.


SDK Flutter: https://github.com/v-modal/vmodal_sdk_flutter
SDK Android: https://github.com/v-modal/vmodal_sdk_android
Discord: https://discord.gg/K72z28KUx

Top comments (0)