Recognition: 2 theorem links
· Lean TheoremStyle Amnesia: Investigating Speaking Style Degradation and Mitigation in Multi-Turn Spoken Language Models
Pith reviewed 2026-05-16 19:23 UTC · model grok-4.3
The pith
Spoken language models lose instructed speaking styles after several conversation turns.
A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.
Core claim
When spoken language models receive an initial instruction to speak in a given style, they exhibit style amnesia and stop maintaining that style after several turns of interaction. This holds across styles including emotion, accent, volume, and speaking speed. The models can retrieve the instruction when prompted later but fail to apply it unless the prompt explicitly recalls it; explicit recall therefore mitigates the amnesia. Adherence is weaker when the style instruction appears in system messages than when it appears in user messages.
What carries the argument
Style amnesia, the progressive loss of adherence to an initial speaking-style instruction over multiple turns in spoken language models.
If this is right
- Explicitly prompting the model to recall the style instruction in later turns restores better style expression.
- Style instructions placed in user messages are followed more consistently than the same instructions placed in system messages.
- No model among the three proprietary and two open-source systems tested sustains the instructed style without mitigation.
- Future spoken language models require new mechanisms to preserve paralinguistic style across extended interactions.
Where Pith is reading between the lines
- Applications that rely on consistent character voices or emotional tone may see reduced user trust as styles shift mid-conversation.
- The same degradation could affect other persistent conversation-level constraints beyond speaking style.
- Adding a dedicated memory store for style parameters might reduce the need for repeated explicit reminders.
- Testing longer dialogues would reveal how rapidly style loss occurs and whether it stabilizes or worsens.
Load-bearing premise
The prompts and style judgments used in the evaluation isolate adherence to speaking style from other model limitations such as general instruction following or output quality.
What would settle it
Run a test in which models receive a style instruction at turn one, then generate responses for five or more turns without any reminder, and measure whether human or automatic judges detect the original style in the later outputs at rates above chance.
Figures
read the original abstract
In this paper, we show that when spoken language models (SLMs) are instructed to speak in a specific speaking style at the beginning of a multi-turn conversation, they cannot maintain the required speaking styles after several turns of interaction; we refer to this as the style amnesia of SLMs. We focus on paralinguistic speaking styles, including emotion, accent, volume, and speaking speed. We evaluate three proprietary and two open-source SLMs, demonstrating that none of these models can maintain a consistent speaking style when instructed to do so. We further show that while SLMs can recall the style instruction when prompted in later turns, they still fail to express it, but through explicit recall can mitigate style amnesia. In addition, SLMs struggle more when the style instruction is placed in system messages rather than user messages, even though system messages are specifically designed to provide persistent, conversation-level instructions. Our findings highlight a systematic gap in current SLMs' ability to maintain speaking styles, highlighting the need for improved style adherence in future models. Our code and evaluation data are publicly available at https://github.com/YuXiangLin1234/SLM-Style-Amnesia.
Editorial analysis
A structured set of objections, weighed in public.
Referee Report
Summary. The paper claims that spoken language models (SLMs) suffer from 'style amnesia,' failing to maintain instructed paralinguistic speaking styles (emotion, accent, volume, speaking speed) over multi-turn conversations despite initial instructions. Evaluations across three proprietary and two open-source models show none maintain consistency; models recall instructions but fail to express them, with explicit recall as mitigation. Performance is worse when instructions are in system messages than user messages. Code and data are publicly released.
Significance. If the results hold, this identifies a systematic limitation in current SLMs for preserving paralinguistic style in interactive settings, relevant for natural spoken dialogue systems. The multi-model empirical evaluation with public code and data provides a reproducible benchmark that can guide improvements in style adherence.
major comments (2)
- [§4] §4 (Evaluation): The style adherence scores (e.g., Table 2) demonstrate degradation, but without ablations comparing style-instructed vs. neutral-instruction conditions or controls for overall coherence decline, it remains unclear whether the measurements isolate style-specific failure from general multi-turn instruction following or generation quality limitations.
- [§5.2] §5.2 (Mitigation): The explicit recall experiments show improved style expression, but the paper should report whether recall prompts affect secondary metrics such as response relevance or turn coherence to confirm the mitigation is style-targeted rather than a general prompt engineering effect.
minor comments (2)
- [Figures] Figure 1 and 2: Add explicit turn-number annotations and error bars to clarify degradation trends across models.
- [Abstract] Abstract: Specify the exact automatic metrics and human evaluation protocol used for style judgment to allow readers to assess reliability upfront.
Simulated Author's Rebuttal
We thank the referee for the constructive feedback on our manuscript. We address each major comment below and have made revisions to strengthen the evaluation and mitigation analyses as suggested.
read point-by-point responses
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Referee: [§4] §4 (Evaluation): The style adherence scores (e.g., Table 2) demonstrate degradation, but without ablations comparing style-instructed vs. neutral-instruction conditions or controls for overall coherence decline, it remains unclear whether the measurements isolate style-specific failure from general multi-turn instruction following or generation quality limitations.
Authors: We agree that the current evaluation would benefit from explicit controls to isolate style-specific degradation. In the revised manuscript, we will add an ablation comparing style-instructed conversations to neutral-instruction baselines, reporting style adherence scores under both conditions. We will also include secondary metrics for overall coherence and response quality across turns to control for general multi-turn decline, ensuring the style amnesia effect is distinguished from broader instruction-following limitations. revision: yes
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Referee: [§5.2] §5.2 (Mitigation): The explicit recall experiments show improved style expression, but the paper should report whether recall prompts affect secondary metrics such as response relevance or turn coherence to confirm the mitigation is style-targeted rather than a general prompt engineering effect.
Authors: We concur that reporting secondary metrics is necessary to confirm the mitigation is style-specific. In the revised version, we will include measurements of response relevance and turn coherence for the explicit recall condition alongside the style adherence improvements. This will demonstrate that the gains in style expression do not result from general prompt engineering effects that might degrade other aspects of conversation quality. revision: yes
Circularity Check
No circularity: purely empirical evaluation of model behavior
full rationale
The paper conducts an empirical study by prompting SLMs with style instructions and measuring degradation via automatic and human judgments across turns. No equations, derivations, fitted parameters, or self-citations are used to derive the central claim; results follow directly from observed outputs on the evaluated models. The work is self-contained against external benchmarks (model responses) with public code and data, satisfying the criteria for an independent empirical finding with no reduction to inputs by construction.
Axiom & Free-Parameter Ledger
axioms (1)
- domain assumption SLMs can interpret and attempt to follow paralinguistic style instructions given in prompts
invented entities (1)
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style amnesia
no independent evidence
Lean theorems connected to this paper
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IndisputableMonolith/Foundation/RealityFromDistinction.leanreality_from_one_distinction unclear?
unclearRelation between the paper passage and the cited Recognition theorem.
none of these models can maintain a consistent speaking style when instructed to do so
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IndisputableMonolith/Cost/FunctionalEquation.leanwashburn_uniqueness_aczel unclear?
unclearRelation between the paper passage and the cited Recognition theorem.
style amnesia... IF rate degrades rapidly in subsequent turns
What do these tags mean?
- matches
- The paper's claim is directly supported by a theorem in the formal canon.
- supports
- The theorem supports part of the paper's argument, but the paper may add assumptions or extra steps.
- extends
- The paper goes beyond the formal theorem; the theorem is a base layer rather than the whole result.
- uses
- The paper appears to rely on the theorem as machinery.
- contradicts
- The paper's claim conflicts with a theorem or certificate in the canon.
- unclear
- Pith found a possible connection, but the passage is too broad, indirect, or ambiguous to say the theorem truly supports the claim.
Reference graph
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ENTRY address archivePrefix author booktitle chapter edition editor eid eprint eprinttype howpublished institution journal key month note number organization pages publisher school series title type volume year doi pubmed url lastchecked label extra.label sort.label short.list INTEGERS output.state before.all mid.sentence after.sentence after.block STRING...
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" write newline "" before.all 'output.state := FUNCTION n.dashify 't := "" t empty not t #1 #1 substring "-" = t #1 #2 substring "--" = not "--" * t #2 global.max substring 't := t #1 #1 substring "-" = "-" * t #2 global.max substring 't := while if t #1 #1 substring * t #2 global.max substring 't := if while FUNCTION word.in bbl.in capitalize " " * FUNCT...
discussion (0)
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