Audio passthrough sends an encoded audio stream onward for another compatible device to decode, rather than decoding it in the source application or box first. The entire connection chain needs to support the chosen format. Passthrough changes where decoding happens; it does not create an unsupported track or add missing audio languages.
A practical example
A player can pass a compatible surround track to a receiver, which then performs the decoding. If the television or an intermediate device cannot carry that arrangement, changing the source to a suitable decoded output can help establish where compatibility fails.
A common misunderstanding
Enabling every passthrough format is not a universal improvement. Select only arrangements supported by the actual equipment, and distinguish passthrough failures from muted speakers or an unavailable audio track.
Related terms
Stable technical definition. Editorial approach