Vowel- and Diphthong-Like Spectral Patterns in Sperm Whale Codas
Bibliographic record
Abstract
Abstract The sperm whale communication system, consisting of groups of clicks called codas, has been primarily analyzed in terms of the number of clicks and their inter-click timing. This paper reports spectral properties in sperm whale vocalizations and demonstrates that spectral properties are highly structured, discretely distributed across codas, and uttered in dialogues, rather than being a physical artefact of whale movement. We report formant structure in whale codas and uncover previously unobserved spectral patterns. We argue that these spectral properties freely combine with the traditionally analyzed properties. We present a visualization technique that allows the description of several previously unobserved patterns. Codas are on many levels analogous to human vowels and diphthongs and can be conceptualized in terms of the source-filter theory: vowel duration and pitch correspond to the number of clicks and their timing (traditional coda types), while spectral properties of clicks correspond to formants in human vowels. We identify two recurrent and discrete coda-level spectral patterns that appear across individual sperm whales and across traditional coda types: the a- and i-coda vowels. We also report that sperm whales have diphthongal patterns on individual codas: with rising, falling, rising-falling and falling-rising formant patterns observed. These uncovered patterns suggest that spectral properties have the potential to add to the communicative complexity of codas independent of the traditionally analyzed properties and add a new dimension to the study of a cetacean communication system.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.002 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".