Voice Search is a default feature on Android devices which lets you search via your voice based on your language. To change voice search language on Android do as follows:
1. Open Settings application
2. Tap Language and input (on some Galaxy devices, you need to go to Controls tab)
3. Under Speech settings, tap Voice Search.
4. Now open Language to select and change voice search language on your Android device.
Some of supported languages are: English, Bahasa Indonesia, Deutsch, Spanish, French, Italian, and Polski