Voice Actions for Android is integrated in the Voice Search app, which is often pre-installed in all Android based smart-phones. In order to ensure that you have the app, you can open up the Google Play Store and search for ‘Voice Search’. If the app is already installed, you are good to go, if not, you should install it first.
Once you have the Voice Search app, you need to place the Google Search widget on a home screen for easy accessibility (if it is not already on one of your screens).
The Google Search Widget is a bar with a microphone icon at the far right. The microphone icon activates the voice search feature and needs to be tapped to use voice commands.
Once you tap the microphone icon, a dialogue box should appear if you are using Android 4.0.x (Ice Cream Sandwich). If your device is running Android 4.1.x (Jelly Bean), the Google Now Search page should open up.
Either way, the new page (with a larger microphone icon) will say ‘Speak Now’, after which you can use the preset voice commands. In our case, we want to play music, for which the voice command is ‘Listen to name-of-song’.
Make sure you have the song/music on your device’s memory. Once you say ‘Listen to name-of-song’, the dialogue box may prompt you to select an app to execute the voice command. You can select your preferred app (for example the default Android Music Player) and check the ‘Use by default for this action’ box to set it as a permanent choice (you can change it later if you want).
Now your selected app should be playing the song you wanted. However, sometimes (in Jelly Bean for instance) the ‘Listen to’ command does not work and will only show you Google search results for your query. In this case, you should try the ‘Play name-of-song’ voice command, which should serve the same function.