An extra audio track can be delivered in two ways
STVR’s official guidance distinguishes premixed audio commentary from receiver-mixed AD. A premix combines description with programme sound before delivery. Receiver mixing sends a separate commentary component for the receiving equipment to combine with ordinary sound. That distinction affects what the receiver must support.
A second audio entry should therefore not be identified solely by its position in the menu. A familiar-looking alternate track can serve another purpose on a programme without description. Begin with an item that STVR marks for audio commentary and use the relevant receiver guidance for that type of delivery.
Three requirements need to meet
STVR identifies the programme’s AD provision, the operator carrying it and the receiver’s ability to process it as separate requirements. A television menu showing an AD preference does not establish all three. Likewise, a broadcaster marking does not prove a particular distributor has carried the required component to your setup.
Write down the selected programme and reception route before experimenting. Antenna reception and an operator’s set-top box can follow different delivery paths. Changing a setting on the television may not affect audio decoded by an external box. Keep the device doing the actual receiving in view.
Mixing and ordinary volume are different controls
Receiver mixing can allow the relationship between description and programme sound to be adjusted on suitable equipment. The existence of that method is not a promise that every receiver exposes the same control. Use the current manufacturer’s instructions for the actual model when a mixing adjustment is needed.
First confirm that the intended description is present. Then choose a passage with dialogue and a pause containing visual information, and judge the balance. Raising the main speaker volume increases everything; it does not necessarily change the relationship between commentary and the ordinary soundtrack.
Keep the test tied to one described item
When comparing settings, stay with the same programme and note the point where commentary should be audible. Moving to another channel introduces a different source and may remove the feature entirely. A short repeatable comparison is more useful than testing unrelated programmes with unknown access arrangements.
If a household uses headphones for one listener, consult the receiver’s documented output behaviour before planning simultaneous described and ordinary sound. STVR explains a capability of receiver mixing; that explanation does not certify every television’s headphone or speaker routing.
Questions answered
Is every second audio track an AD track?
No. Confirm the programme marking and the documented delivery method.
Can a broadcaster AD label establish operator and receiver support?
No. STVR treats those as separate requirements.
Sources & further reading
Official references for the subjects discussed. Service terms and device software can change.