This is a pretty interesting theory. 1. The listener determines the meaning of what the speaker said. 2. The listener determines the emotional significance of

This is a pretty interesting theory. 1. The listener determines the meaning of what the speaker said. 2. The listener determines the emotional significance of the meaning of what the speaker said. 3. The listener determines whether of not the speaker's speech is spontaneous. 4. The listener determines their belief about the truth of what the speaker said, but, the amount of effort put into this determination is proportional to the perceived level of spontaneity in the speaker's speech. 5. The listener responds to the speaker, where their response includes an indication of their belief about the truth of what the speaker said. I think the truth-value part of this might be off track. Here's a slightly different hypothesis: Speech carries two separate signals: information and emotion. The former is world-state data, and the latter is signal about the emotional state of the speaker. In a social species like humans, both are critical. We might process those two channels of data with different parts of our brain even though the source signal has them merged together into one single sound. Imagine an audio processing pipeline that strips the literal informational content out and shunts it one way and takes the emotional affect another way. The informational content needs to be processed actively with full attention from our frontal cortex. We have to pay attention to it. We don't seem to absorb detailed information "in the background" well. I don't know anyone who can, say, read a book and listen to a non-fiction podcast at the same time. Emotional content doesn't need our active attention. It's something we can absorb passively. We use words like "feel", "vibe", "mood", and "ambience" to describe it. OK, so you've got a speech-like sound that contains information and emotion. How do you decide how much attention to pay to it? Information is more likely to be useful if it's fresh, so sounding spontaneous is a positive signal for information content. As the author supposes, music is a negative superstimulus for that. It's audio that contains no informational content and only emotion, which it telegraphs by sounding extremely rehearsed (repetitive rhythm, wide melodic swings). That lets our brain know that we don't have to pay active, logical attention to it. That's pleasant because it frees us to think about what we like while absorbing the music emotionally in the background. This helps explain why some like me do like listening to music while programming, but not music with lyrics. Non-lyrical music helps me focus my attention on code because it sends a signal that I don't have to pay attention to it. This may also explain why religions, cults, and demogogues use such sing-song like speaking styles: it encourages the audience to mentally switch off and not think as critically about what they are hearing as they might otherwise.