Auditory Cataloguing

Auditory Cataloguing is the standardized Tower-wide practice for the identification, classification, and archival recording of sound-based phenomena. Governed by Concordance 47 and its myriad amendments, it is distinct from the mere perception of sound; a phenomenon must undergo formal Auditory Confirmation to be considered suitable for cataloguing and thus real within the Tower’s ontological framework.

Procedural Framework

The process is initiated upon the detection of an auditory phenomenon, which is temporarily housed in The Vestibule of Auditory Phantoms for triage. A Librarian-designated Receiver then submits a Form 47-A (Phenomenon Hearing) to the local Auditory Permit Office. If the sound is deemed to have "sufficient persistent intent," it enters the queue for the next Auditory Phase, during which it will undergo Confirmation. Confirmed sounds are assigned a Resonance Index (RI) and a Catalogue Number (CN), prefixed by the floor of primary residence (e.g., FL.331.α-47).

Unconfirmed or residual sounds are classified under Auditory Anomalies and are either relegated to provisional ledgers, such as the Whispering Ledgers of Floor 909, or transferred to specialized holding areas like The Whispering Gallery or the Western Spire for long-term study. The backlog of all pending phenomena is officially tracked in the Grand Ledger of Auditory Potential.

Taxonomic Categories

Auditory Catalogue entries are organized hierarchically:

1. Constitutive Sounds: Sounds that, upon cataloguing, materially alter their immediate environment according to the Axiom of Constitutive Resonance. The hum catalogued on Thirty-Sixth Landing in 12-σ-47, which subsequently solidified the air into glass panels, is a canonical example.
2. Echoic Imprints: Repetitive or resonant phenomena lacking a clear point of origin, often catalogued in bulk. These are the primary holdings of floors like Floor 17419 (The Chamber of Coincidental Echoes).
3. Phantom Compositions: Incomplete or endlessly looping musical works, such as those found in Fl. 331.
4. Auditory Residue: The faint, persistent after-effect of a decatalogued or dissipated sound, managed by the Spire of Auditory Phantoms.

Jurisdictional Disputes

A persistent scholarly controversy concerns the cataloguing of implied sound. The "Silent Chorus" incident of 89--12 involved a visual cataloguing on Floor 4501 (The Pantomime Archive) depicting 34 figures in a state of apparent song. Proponents from the Spire of Auditory Phantoms argued the visual evidence constituted a "pre-confirmed auditory potential" requiring immediate cataloguing, while traditionalists held that without a detectable acoustic waveform, no procedure could be initiated. The matter was provisionally resolved by Concordance 89, Amendment δ, which created the category of "Pre-Catalogued Auditory Space," though the practical application remains contentious.

Further disputes arise between the Western Spire and the Spire of Auditory Phantoms regarding ownership of sub-auditory phenomena (vibrations below 20 Hz). The former claims jurisdiction under its charter for "metaphysical resonance," while the latter asserts all vibrational energy falls under the broad mandate of Auditory Anomalies. This has led to duplicate cataloguing on several occasions, most notably for the "Sub-Basement Drone" recorded on both Fl. -47 (Western Spire) and Fl. 22002 (Spire of Auditory Phantoms).

Physical Manifestation & Storage

Upon cataloguing, a sound is not merely recorded but is instanced within the Tower. This often requires architectural adaptation. A catalogued echo may manifest as a permanent whisper along a specific corridor; a symphonic phrase might require the construction of a resonant chamber. The management of this physical Auditory Residue and the permitting for structural modifications fall under Auditory Permitting, a process notorious for its backlog, often forcing newly catalogued sounds to reside temporarily in acoustically incompatible spaces, leading to contamination and conflation.

Historical Development

The practice was formalized in the 47th Auditory Phase, concurrent with the ratification of Concordance 47. Prior to this, auditory phenomena were logged haphazardly within visual or tactile catalogues, leading to significant ontological leakage. The establishment of the Vestibule and the Confirmation procedure standardized reality thresholds for sound. The Great Auditory Phase of 12-ω-01 saw the bulk cataloguing of over 2 million residual echoes, populating the newly constructed Whispering Gallery and establishing the need for the specialized ledgers on Floor 909.

"A sound unheard by the Catalogue is a vibration without consequence; a sound entered therein becomes a fact of the Tower." — Preface to the Revised Auditory Catalogue, Vol. I

The system, while robust, is perpetually strained by the Tower’s infinite acoustic input. Debates continue on whether to lower the Confirmation threshold to clear the Grand Ledger backlog, or to further refine categories to prevent future jurisdictional overlap.