Introduction

There you are at the opera house. The soprano has just hit her high note – a glass-shattering high C that fills the hall – and she holds it. She holds it. She holds it. She holds it. She holds it. She holds the note for such a long time that after a while a funny thing happens: You no longer seem only to hear it, the note as it is currently sounding, that glass-shattering high C that is loud and high and pure. In addition, you also seem to hear something more. It is difficult to express precisely what this extra feature is. One is tempted to say, however, that the note now sounds as though it has been going on for a very long time. Perhaps it even sounds like a note that has been going on for too long. In any event, what you hear no longer seems to be limited to the pitch, timbre, loudness, and other strictly audible qualities of the note. You seem in addition to experience, even to hear, something about its temporal extent.

This is a puzzling experience. For surely, it seems, you never actually hear anything but the note as it is currently sounding. You never actually hear anything, one might have thought, except for the current audible qualities of the note.