Audioproprioceptive sensory substitution: A test case for acquaintance

Interaction with distal sensory stimuli affords experience of those stimuli, experience which affords acquaintance. What is the role of phenomenal character in this acquaintance? There are two camps on this question. The intrusion camp holds that stimuli character becomes part of experience's phenomenal character. Phenomenal character reveals stimuli, allowing them to intrude into experience. The mere-sign camp holds that phenomenal character is merely a sign which conveys usable information about stimuli without ``unveiling'' them. Typical cases of perceptual experience fail to settle the debate, because compelling intuitions can be marshaled from them supporting either camp. To advance the discussion, unusual cases must be considered. For example, type-2 blindsight has been proposed by some as a case supporting the mere-sign camp and telling against the intrusion camp. I’ve argued elsewhere that type-2 blindsight experiences don’t help, since they fail to afford acquaintance of stimuli at all. In this paper, I consider another case: the experiences had during audioproprioceptive sensory substitution. I argue that, counter to initial intuitions, these experiences support the intrusion camp, not the mere-sign camp.