Jul 2026· International Conference on Signal Processing and Communications· pp. 1-5· 0 citations· 27 references
Abstract
Developing Automatic Speech Recognition (ASR) systems for specialized medical domains is challenging in lowresource settings due to the limited availability of annotated speech data. Synthetic speech generated using text to speech (TTS) systems is often used to augment training data, but directly mixing synthetic and real speech can introduce distribution mismatch that degrades encoder representations. This work introduces Real-Governed Representation-Calibrated Training (RG-RCT), a training strategy that regulates the influence of synthetic speech at the representation level. The proposed framework combines reliability-based confidence estimation, representation alignment, and layer-wise representation governance to stabilize the encoder feature space while preserving acoustic diversity from multi-speaker synthetic data. Experiments on medical-domain speech datasets using Wav2Vec2 and Whisper demonstrate that RG-RCT consistently outperforms conventional strategies such as direct mixing and confidence-aware training. The proposed method achieves the lowest Word Error Rate (WER), reaching 17.1% and 16.6% for Telugu and 23.3% and 25.6% for Kannada. These results indicate that regulating encoder representation geometry enables more effective utilization of synthetic speech for low-resource medical ASR.
This paper investigates how multilingual medical adaptation reshapes the internal representations of Whisper models through layer-wise encoder analysis, and shows that English medical fine-tuning produces the dominant encoder shift, whereas multilingual continuation largely preserves the adapted representation space.
Souranil Kahali, Rituparna Bose, Abner Hernandez et al.· 0 citations
This work presents a Burmese medical speech recognition framework built on a high-quality 28-hour corpus recorded and validated by native speakers, and fine-tune Whisper models using full fine-tuning (FFT) and parameter-efficient fine-tuning (PEFT) with LoRA.
Ye Kyaw Thu, Y. Lin, Thura Aung et al.· 0 citations
This study proposes a multi-stage intelligent documentation framework that integrates a 12-layer Conformer architecture, BERT-BiLSTM-CRF semantic modeling, and BART-based structured text generation that illustrates the effectiveness of deep time-frequency feature extraction and contextual sequence modeling for complex noisy signals.
X. Zou, L. Wang, J. Sun et al.· Advanced Electromagnetics· 0 citations
Developing artificial intelligence capable of clinical language comprehension and reliable diagnostic reasoning has remained a core challenge in biomedical engineering. While Large Language Models (LLMs) demonstrate significant potential in general natural language processing tasks, their direct application in the medical domain is severely constrained by parametric hallucinations and data silos. This paper introduces an end-to-end, resource-efficient, multilingual speech-driven Question-Answering (QA) framework optimized for localized clinical support. To accommodate deployment on consumer-grade execution environments, we implement Parameter-Efficient Fine-Tuning (PEFT) using Low-Rank Adaptation (LoRA) and 4-bit Quantized LoRA (QLoRA) configurations across open-source 3B and 7B parameter architectures. Human preference alignment is enforced via a stateful Reinforcement Learning with Human Feedback (RLHF) loop applying Proximal Policy Optimization (PPO). Crucially, to mitigate the vulnerabilities of passive information retrieval, we introduce an Active Validation Loop powered by Corrective Retrieval-Augmented Generation (CRAG). This validation engine is decoupled from the model harness using the Model Context Protocol (MCP), standardizing asynchronous lookups across dense vector repositories, clinical guidelines, and real-time electronic health registries.
Misha Patel· International Journal of Sci...· 0 citations
Synthetic speech provides scalable supervision for automatic speech recognition (ASR), but its benefit depends on the selected texts, reference speech, and amount of synthesized data. We present a unified phoneme-based TTS-to-ASR augmentation pipeline built around a multilingual TTS model trained from scratch using the F5-TTS architecture with language-ID conditioning. The pipeline combines language-specific grapheme-to-phoneme conversion, reference-speech filtering, candidate-text selection, synthesis, and matched ASR continuation. We further propose phoneme-frequency-guided selection (PFGS), which ranks candidate sentences using phoneme frequencies estimated from real ASR training labels. Experiments with separate monolingual ASR systems for Arabic, French, Italian, and Portuguese span 13 test sets. Across the synthesis-scale sweep, random augmentation improves over matched real-only continuation on 11 test sets. Under a nominal 60% synthesis budget, PFGS improves over real-only training on 12 test sets and over random selection on 9. Its largest relative word error rate (WER) reduction against random selection is 19.3%. With target texts and synthesis counts fixed, reference-speech filtering reduces absolute WER by 0.29 and 0.59 points on Italian and French Common Voice, respectively. These results identify synthesis scale, candidate-text content, and reference quality as important control variables in TTS-based ASR augmentation.
Zhen Wang, Tian-Rui Wu, Rong-Qi Han et al.· 0 citations
Automatic speech recognition (ASR), or speech-to-text (STT), is becoming an important interface for AI systems in diagnostic workflows, but general-purpose ASR models often degrade in specialized technical domains. In diagnostic applications such as fault identification, root cause analysis, and repair recommendation, general-purpose ASR systems struggle with domain-specific terminology, abbreviations, part identifiers, and measurement expressions, leading to elevated transcription errors. This work presents a domain adaptation pipeline that unifies three components: a synthetic benchmarking framework in which domain-specific technical text is converted to speech via text-to-speech~(TTS) synthesis and transcribed by open-source ASR models to establish baseline performance; Low-Rank Adaptation~(LoRA)-based fine-tuning of Whisper Large-v3 using those synthetic audio-text pairs; and transfer validation on curated real-world automotive YouTube recordings to assess generalization beyond synthetic conditions. Using automotive technical language as a representative diagnostic domain, a data-scaling study employing progressively larger subsets of in-domain training data evaluates performance on a held-out test set via word error rate~(WER), character error rate~(CER), normalized error metrics, alphanumeric error rate, semantic similarity, and Bidirectional Encoder Representations from Transformers Score~(BERTScore). Results show consistent gains from lightweight domain adaptation on both held-out synthetic data and real-world recordings, confirming that synthetic data generation combined with LoRA-based fine-tuning is an effective and computationally practical strategy for improving ASR accuracy in specialized technical domains where labeled speech is scarce.
Aman Kumar, Ahmed K. Farahat, Huimin Zhuge et al.· PHM Society European Confere...· 0 citations