# Analyzing and Fine-Tuning Whisper Models for Multilingual Pilot Speech Transcription in the Cockpit

arXiv: https://arxiv.org/abs/2506.21990 · HTML: https://mlsanity.com/paper/2506.21990/

## Key facts

- No citing papers in the map yet (data through 14 Oct 2026).
- Builds on 10 of its 22 references that are in the map.
- First posted on arXiv 27 Jun 2025.

## Builds on (most cited first, 10 of 10)

- [LoRA: Low-Rank Adaptation of Large Language Models](https://mlsanity.com/paper/2106.09685/) (2021)
- [wav2vec 2.0: A Framework for Self-Supervised Learning of Speech Representations](https://mlsanity.com/paper/2006.11477/) (2020)
- [Shortcut Learning in Deep Neural Networks](https://mlsanity.com/paper/2004.07780/) (2020)
- [Common Voice: A Massively-Multilingual Speech Corpus](https://mlsanity.com/paper/1912.06670/) (2019)
- [Deep Speech 2: End-to-End Speech Recognition in English and Mandarin](https://mlsanity.com/paper/1512.02595/) (2015)
- [GigaSpeech: An Evolving, Multi-domain ASR Corpus with 10,000 Hours of Transcribed Audio](https://mlsanity.com/paper/2106.06909/) (2021)
- [The People's Speech: A Large-Scale Diverse English Speech Recognition Dataset for Commercial Usage](https://mlsanity.com/paper/2111.09344/) (2021)
- [BigSSL: Exploring the Frontier of Large-Scale Semi-Supervised Learning for Automatic Speech Recognition](https://mlsanity.com/paper/2109.13226/) (2021)
- [SpeechStew: Simply Mix All Available Speech Recognition Data to Train One Large Neural Network](https://mlsanity.com/paper/2104.02133/) (2021)
- [Whisper Finetuning on Nepali Language](https://mlsanity.com/paper/2411.12587/) (2024)

## Abstract (arXiv)

The developments in transformer encoder-decoder architectures have led to significant breakthroughs in machine translation, Automatic Speech Recognition (ASR), and instruction-based chat machines, among other applications. The pre-trained models were trained on vast amounts of generic data over a few epochs (fewer than five in most cases), resulting in their strong generalization capabilities. Nevertheless, the performance of these models does suffer when applied to niche domains like transcribing pilot speech in the cockpit, which involves a lot of specific vocabulary and multilingual conversations. This paper investigates and improves the transcription accuracy of cockpit conversations with Whisper models. We have collected around 85 minutes of cockpit simulator recordings and 130 minutes of interview recordings with pilots and manually labeled them. The speakers are middle aged men speaking both German and English. To improve the accuracy of transcriptions, we propose multiple normalization schemes to refine the transcripts and improve Word Error Rate (WER). We then employ fine-tuning to enhance ASR performance, utilizing performance-efficient fine-tuning with Low-Rank Adaptation (LoRA). Hereby, WER decreased from 68.49 % (pretrained whisper Large model without normalization baseline) to 26.26% (finetuned whisper Large model with the proposed normalization scheme).