Begin with Automatic
On Streamer, open All settings, Display and Sound, Audio options, Output format. Google lists Automatic alongside specific Dolby and PCM stereo choices. Automatic is a useful baseline because the system attempts to choose the available route.
If you choose a specific format, confirm that the connected audio equipment supports it. A surround option is not a quality upgrade when the downstream device cannot decode it. Keep the previous working choice in your notes before changing it.
Use a bounded listening comparison
Play the same familiar passage after a change and check dialogue, complete silence and timing. Keep the television and receiver processing fixed. A successful stereo test answers whether that route carries usable audio; it does not prove every surround soundtrack has been tested.
If an output change needs the restart described in Google’s current instructions, complete that procedure before evaluating the result. Otherwise a comparison can be made against a setting that has not fully taken effect.
Treat sound processing as another layer
Dialogue enhancement, leveling and receiver offsets change other aspects of the listening route. Avoid changing them alongside the output format. If the complaint is lip sync rather than silence, inspect the exact symptom before adding another correction.
When seeking support, provide the Streamer model, chosen output format and receiver or soundbar model. A service name by itself does not describe the audio capabilities of the equipment.
Questions answered
Are Output format controls identical on every Chromecast?
No. Google identifies the Output format menu as a Google TV Streamer feature.
Is forcing Dolby always better than Automatic?
No. The selected format must be supported by the entire audio route.
Sources & further reading
Official references for the subjects discussed. Service terms and device software can change.