activity
20162026
most citedA Comprehensive Study of Deep Bidirectional LSTM RNNs for Acoustic Modeling in Speech Recognition

173 citations · 306 across the 58 of their papers we have counts for

collaborators

63 papers

cs.CL2026

A Systematic Comparison of Search Space Complexity and Efficiency for Time-Synchronous End-to-End ASR Models

Simon Berger, Larissa Kleppel, Ralf Schlüter

Search is a central component of Automatic Speech Recognition (ASR) systems and has been deeply investigated for classical ASR modeling based on Hidden Markov Models (HMMs). Howeve…

cs.CL2026

Gradient-Based Speech-to-Text Alignment for Any ASR Model: From CTC to Speech LLMs

Albert Zeyer, Ralf Schlüter, Hermann Ney

Speech-to-text alignment means finding the temporal boundaries of each word in the audio. Some models provide such an alignment directly and others do not. Connectionist temporal c…

cs.CL2026

Revisiting the Relation Between Language Model Perplexity and ASR Word Error Rate for Modern End-to-End Speech Recognition

Mohammad Zeineldeen, Albert Zeyer, Haoran Zhang +3

Language model (LM) perplexity (PPL) has historically been used as a proxy for automatic speech recognition (ASR) word error rate (WER), with prior work reporting an approximately…

cs.CL2026

Text-Utilization for Encoder-dominated Speech Recognition Models

Albert Zeyer, Tim Posielek, Ralf Schlüter +1

This paper investigates efficient methods for utilizing text-only data to improve speech recognition, focusing on encoder-dominated models that facilitate faster recognition. We pr…

cs.CL2026

Diffusion Language Models for Speech Recognition

Davyd Naveriani, Albert Zeyer, Ralf Schlüter +1

Diffusion language models have recently emerged as a leading alternative to standard language models, due to their ability for bidirectional attention and parallel text generation.…

eess.AS2026

LLMs and Speech: Integration vs. Combination

Robin Schmitt, Albert Zeyer, Mohammad Zeineldeen +2

In this work, we study different approaches to utilize large language models (LLMs) for automatic speech recognition (ASR). Specifically, we compare the tight integration of an aco…

cs.NE2025

Reproducing and Dissecting Denoising Language Models for Speech Recognition

Dorian Koch, Albert Zeyer, Nick Rossenbach +2

Denoising language models (DLMs) have been proposed as a powerful alternative to traditional language models (LMs) for automatic speech recognition (ASR), motivated by their abilit…

eess.AS2025

Error Analysis in a Modular Meeting Transcription System

Peter Vieting, Simon Berger, Thilo von Neumann +3

Meeting transcription is a field of high relevance and remarkable progress in recent years. Still, challenges remain that limit its performance. In this work, we extend a previousl…

cs.SD2025

A Comparative Analysis on ASR System Combination for Attention, CTC, Factored Hybrid, and Transducer Models

Noureldin Bayoumi, Robin Schmitt, Tina Raissi +3

Combination approaches for speech recognition (ASR) systems cover structured sentence-level or word-based merging techniques as well as combination of model scores during beam sear…

cs.CL2025

Exploring Gender Bias in Large Language Models: An In-depth Dive into the German Language

Kristin Gnadt, David Thulke, Simone Kopeinik +1

In recent years, various methods have been proposed to evaluate gender bias in large language models (LLMs). A key challenge lies in the transferability of bias measurement methods…

cs.SD2025

Label-Context-Dependent Internal Language Model Estimation for CTC

Zijian Yang, Minh-Nghia Phan, Ralf Schlüter +1

Although connectionist temporal classification (CTC) has the label context independence assumption, it can still implicitly learn a context-dependent internal language model (ILM)…

eess.AS2025

Regularizing Learnable Feature Extraction for Automatic Speech Recognition

Peter Vieting, Maximilian Kannen, Benedikt Hilmes +2

Neural front-ends are an appealing alternative to traditional, fixed feature extraction pipelines for automatic speech recognition (ASR) systems since they can be directly trained…

cs.LG2025

Analyzing the Importance of Blank for CTC-Based Knowledge Distillation

Benedikt Hilmes, Nick Rossenbach, Ralf Schlüter

With the rise of large pre-trained foundation models for automatic speech recognition new challenges appear. While the performance of these models is good, runtime and cost of infe…

cs.LG2025

Classification Error Bound for Low Bayes Error Conditions in Machine Learning

Zijian Yang, Vahe Eminyan, Ralf Schlüter +1

In statistical classification and machine learning, classification error is an important performance measure, which is minimized by the Bayes decision rule. In practice, the unknow…

eess.AS2024

The Conformer Encoder May Reverse the Time Dimension

Robin Schmitt, Albert Zeyer, Mohammad Zeineldeen +2

We sometimes observe monotonically decreasing cross-attention weights in our Conformer-based global attention-based encoder-decoder (AED) models, Further investigation shows that t…

cs.IT2024

Refined Statistical Bounds for Classification Error Mismatches with Constrained Bayes Error

Zijian Yang, Vahe Eminyan, Ralf Schlüter +1

In statistical classification/multiple hypothesis testing and machine learning, a model distribution estimated from the training data is usually applied to replace the unknown true…

cs.CL2024

On the Problem of Text-To-Speech Model Selection for Synthetic Data Generation in Automatic Speech Recognition

Nick Rossenbach, Ralf Schlüter, Sakriani Sakti

The rapid development of neural text-to-speech (TTS) systems enabled its usage in other areas of natural language processing such as automatic speech recognition (ASR) or spoken la…

cs.SD2024

Investigating the Effect of Label Topology and Training Criterion on ASR Performance and Alignment Quality

Tina Raissi, Christoph Lüscher, Simon Berger +2

The ongoing research scenario for automatic speech recognition (ASR) envisions a clear division between end-to-end approaches and classic modular systems. Even though a high-level…

cs.CL2024★ 3 cited

On the Effect of Purely Synthetic Training Data for Different Automatic Speech Recognition Architectures

Benedikt Hilmes, Nick Rossenbach, and Ralf Schlüter

In this work we evaluate the utility of synthetic data for training automatic speech recognition (ASR). We use the ASR training data to train a text-to-speech (TTS) system similar…

eess.AS2024

Medical Spoken Named Entity Recognition

Khai Le-Duc, David Thulke, Hung-Phong Tran +4

Spoken Named Entity Recognition (NER) aims to extract named entities from speech and categorise them into types like person, location, organization, etc. In this work, we present V…

cs.CL2023

On the Relevance of Phoneme Duration Variability of Synthesized Training Data for Automatic Speech Recognition

Nick Rossenbach, Benedikt Hilmes, Ralf Schlüter

Synthetic data generated by text-to-speech (TTS) systems can be used to improve automatic speech recognition (ASR) systems in low-resource or domain mismatch tasks. It has been sho…

cs.CL2023

Investigating the Effect of Language Models in Sequence Discriminative Training for Neural Transducers

Zijian Yang, Wei Zhou, Ralf Schlüter +1

In this work, we investigate the effect of language models (LMs) with different context lengths and label units (phoneme vs. word) used in sequence discriminative training for phon…

cs.LG2023

End-to-End Training of a Neural HMM with Label and Transition Probabilities

Daniel Mann, Tina Raissi, Wilfried Michel +2

We investigate a novel modeling approach for end-to-end neural network training using hidden Markov models (HMM) where the transition probabilities between hidden states are modele…

cs.SD2023

On the Relation between Internal Language Model and Sequence Discriminative Training for Neural Transducers

Zijian Yang, Wei Zhou, Ralf Schlüter +1

Internal language model (ILM) subtraction has been widely applied to improve the performance of the RNN-Transducer with external language model (LM) fusion for speech recognition.…