I picked up the answer at this forum post: Sound Pickup Based On Pawn Not Camera - Cinematics & Media - Unreal Engine Forums
Basically, it can be done in C++ as it is not exposed in Blueprints. You must override the virtual function GetAudioListenerPosition()
My own implementation goes like this:
void ADialoguesPlayerController::GetAudioListenerPosition(FVector & OutLocation, FVector & OutFrontDir, FVector & OutRightDir)
{
OutLocation = GetPawn()->GetActorLocation();
OutFrontDir = GetPawn()->GetActorForwardVector();
OutRightDir = GetPawn()->GetActorRightVector();
}