 The main barrier to an alternative is that the relation between sounds and ordinary things or happenings is commonly understood as causal (see, e.g., Nudds 2001). Awareness as of an effect does not itself typically furnish epistemically unmediated awareness of its cause. Seeing smoke is not seeing fire. The right sort of dependence between characteristics of the experience and the cause is not apparent, and awareness as of an effect does not by itself ground perceptual demonstratives that concern the cause. The metaphysical indirectness of the causal relation appears to block epistemic directness (see O’Callaghan 2011a for further discussion).