I created a plugin for Android Studio called "Build Finish Notifier". With this plugin, you can receive a sound notification when the build is completed. I developed it because I often switch to other tasks, like checking Slack or reading documents, after hitting the run button, and sometimes forget that I've started a build. If you face a similar situation, why not give this plugin a try? You can download it from the Android Studio plugin marketplace under the name Build Finish Notifier. It supports most versions of Android Studio.