openHAB is able to play sound either from the file system (files need to be put in the folder `conf/sounds`), from URLs (e.g. Internet radio streams) or generated by text-to-speech engines (which are available as optional [Voice add-ons]({{base}}/addons/voice.html)).
| `javasound` | System Speaker | This uses the JRE sound drivers to play audio to the local sound interface. |
| `enhancedjavasound` | System Speaker (with mp3 support) | This uses the JRE sound drivers plus an additional 3rd party library, which adds support for mp3 files. |
| `webaudio` | Web Audio | Convenient, if sounds should not be played on the server, but on the client: This sink sends the audio stream through HTTP to web clients, which then cause it to be played back by the browser. Obviously, the browser needs to be opened and have a compatible openHAB UI running. Currently, this feature is supported by Paper UI and HABPanel. |
You can define the default audio sink either by textual configuration in `conf/services/runtime.cfg` or in the Paper UI in `Configuration->System->Audio`.
Alternatively the [`playSound()` function](https://www.eclipse.org/smarthome/documentation/javadoc/org/eclipse/smarthome/model/script/actions/Audio.html#playSound-java.lang.String-) can be used in DSL rules:
You can define a default TTS service and a default voice to use either by textual configuration in `conf/services/runtime.cfg` or in the Paper UI in `Configuration->System->Voice`.
Alternatively you can execute such commands within DSL rules by using the [`say()` function](https://www.eclipse.org/smarthome/documentation/javadoc/org/eclipse/smarthome/core/voice/VoiceManager.html#say-java.lang.String-):
The Android app is [not yet adapted to the openHAB 2 voice features](https://github.com/openhab/openhab.android/issues/242).
To still use the voice feature you will need to have a String item with the name "VoiceCommand" defined, to which the app sends any recognized text as a string command.
| `rulehli` | Rule-based Interpreter | This mimics the behavior of the Android app - it sends the string as a command to a (configurable, default is "VoiceCommand") item and expects a rule to pick it up and further process it. |
| `system` | Built-in Interpreter | This is a simple implementation that understands basic home automation commands like "turn on the light" or "stop the music". It currently supports only English, German and French and the vocabulary is still very limited. The exact syntax still needs to be documented, for the moment you need to refer to the [source code](https://github.com/eclipse/smarthome/blob/master/bundles/core/org.eclipse.smarthome.core.voice/src/main/java/org/eclipse/smarthome/core/voice/internal/text/StandardInterpreter.java#L37). |
The default human language interpreter will be used.
In case of interpretation error, the error message will be said using the default voice and default audio sink.
Again, such a command can also be entered within DSL rules (using the [`interpret()` function](https://www.eclipse.org/smarthome/documentation/javadoc/org/eclipse/smarthome/core/voice/VoiceManager.html#interpret-java.lang.String-))
```java
interpret("turn on the light")
var String result = interpret("turn on the light", "system")
result = interpret("turn on the light", "system", null)
result = interpret(VoiceCommand.state, "system", "sonos:PLAY5:kitchen")
```
You can select a particular human language interpreter (second parameter) and a particular audio sink (third parameter).
The audio sink parameter is used when the interpretation fails; in this case, the error message is said using the default voice and the provided audio sink.
If the provided audio sink is set to null, the error message will not be said.
If no human language interpreter or no audio sink is provided, the default human language interpreter and default audio sink will be used.
The interpretation result is returned as a string.
Note that this result is always a null string with the rule-based Interpreter (rulehli).