Google has updated its Google Voice Android App with an ability to intake 5 different languages at a time and 1 language per line. It is great improvement and feature which Google Voice have got of handling multiple languages at a time.
Earlier you were able to select different languages by changing the languages (more than 50) from settings menu. Now you can switch languages at once, and then change between those 5 languages as you want without going into settings. You can preselect five languages by going to Search => Settings => Voice => Languages. After changing you don’t need to bother about switching as Google will automatically shift to different language as you speak.
There are few limitations also as you need to stick to one language per sentence, but that seems rather reasonable. The other thing is you will be replied with the language you use as search can’t yet reply vocally.
You can download the latest version of the Google search from the Play Store directly.