Stanisław Kacprzak

• PhD
• Professor (Assistant) at AGH University of Krakow

In this paper we suggest to apply a new feature, called Minimum Energy Density (MED), in discrimination of audio signals between speech and music. Our method is based on the analysis of local energy for 1 or 2.5 seconds audio signals. An elementary analysis of the probability for the power distribution is an effective tool supporting the decision m...

Hallucinations of deep neural models are amongst key challenges in automatic speech recognition (ASR). In this paper, we investigate hallucinations of the Whisper ASR model induced by non-speech audio segments present during inference. By inducting hallucinations with various types of sounds, we show that there exists a set of hallucinations that a...

Prediction of speaker's height is of interest for voice forensics, surveillance, and automatic speaker profiling. Until now, TIMIT has been the most popular dataset for training and evaluation of the height estimation methods. In this paper, we introduce HeightCeleb, an extension to VoxCeleb, which is the dataset commonly used in speaker recognitio...

The aim of speech enhancement is to improve speech signal quality and intelligibility from a noisy microphone signal. In many applications, it is crucial to enable processing with small computational complexity and minimal requirements regarding access to future signal samples (look-ahead). This paper presents signal-based causal DCCRN that improve...

GlossoVR is a virtual reality (VR) application that combines training in public speaking in front of a virtual audience and in voice emission in relaxation exercises. It is accompanied by digital signal processing (DSP) and artificial intelligence (AI) modules which provide automatic feedback on the vocal performance as well as the behavior and psy...

In classification tasks, the classification accuracy diminishes when the data is gathered in different domains. To address this problem, in this paper, we investigate several adversarial models for domain adaptation (DA) and their effect on the acoustic scene classification task. The studied models include several types of generative adversarial ne...

A new VR application for voice and speech training has emerged from a problem observable in everyday life: an anxiety of public speaking. In the design process, we incorporated both domain knowledge of experts as well as research with end-users in order to explore the needs and the context of the problem. Functionalities of the prototype are the ef...

Phones for 239 non-annotated languages were selected by automatic segmentation based on changes of energy in the time-frequency representation of speech signals. Phone boundaries were set at location of relatively major changes in energy distribution between seven frequency bands. A vector of average energies calculated for eleven frequency bands w...

In this paper, we examine the use of i-vectors both for age regression as well as for age classification. Although i-vectors have been previously used for age regression task, we extend this approach by applying fusion of i-vectors and acoustic features regression to estimate the speaker age. By our fusion we obtain a relative improvement of 12.6%...

The automatic segmentation and parametrization based on the frequency analysis was used to compare with manually annotated phones. The phones boundaries were fixed in places of relatively large changes in the energy distribution between the frequency bands. Frequency parametrization and clustering enabled the division of phones into groups (cluster...

A comparative analysis of multi-language speech samples is conducted using acoustic characteristics of phoneme realisations in spoken languages. Different approaches to investigation of phonemic diversity in the context of language evolution are compared and discussed. We introduced our approach (materials and methods) and presented preliminary res...

The paper presents the possibility of automatic speech processing in order to determine the acoustic similarity between phones. Subsequent processing steps of recorded speech signal result in phones’ segmentation, even without prior knowledge of their boundaries. The use of frequency signal parameterization and clustering algorithms facilitates a d...

The results of investigation of the differences among the phonemes of 574 languages all over the world are presented. We attempt to verify the hypothesis of African origin for all languages and gradual languages diversification on other parts of the globe. The obtained results justify the languages classification by applying the methods used in evolu...