Guilherme Campos

• PhD
• Professor at University of Aveiro

[This corrects the article DOI: 10.1371/journal.pone.0281680.].

Clinical auditory alarms are often found in hospital wards and operating rooms. In these environments, regular daily tasks can result in having a multitude of concurrent sounds (from staff and patients, building systems, carts, cleaning devices, and importantly, patient monitoring devices) which easily amount to a prevalent cacophony. The negative...

Listening tests are often an essential part of sound design but can be re- source intensive to carry out. Where there are many degrees of freedom in the sound design parameters, the ‘curse of dimensionality’, means that the number of trials re- quired to reliably understand the impact of a particular design variable increases ex- ponentially with i...

Recent research and amendments to standards have called for a paradigm shift when designing for healthcare spaces. While these are currently populated with melodic, hard to learn alarms and other noise sources, the benefits of harmonious alarms inside healing soundscapes seem promising for patients. We propose alarms for the Temperature IEC 60601-1...

The development of computerised diagnosis tools based on lung auscultation necessitates appropriate validation. So far, this work front has received insufficient attention from researchers; validation studies found in the literature are largely flawed. We believe that building open-access crowd-sourced information systems based on large-scale repos...

This communication is an overview of the FCT-funded three-year research project ‘AcousticAVE – Auralisation Models and Applications in Virtual Reality Environments’, a collaboration between the Universities of Aveiro (UA - IEETA) and Minho (UM - CIPsi, LVP). The project involved the development of auralisation software based on the image-source met...

Neste trabalho é apresentado um sistema de realidade aumentada áudio 3D (binaural) para dispositivos móveis iOS. O sistema tira partido dos recursos de processamento e entrada/saída existentes num dispositivo iOS para obter a posição do utilizador recorrendo a um sistema de localização acústico e da unidade de medição inercial (IMU) existente no di...

This paper describes a collaborative platform for camellia cultivar identification harnessing the capabilities of modern information and communication technologies, currently being developed in the context of the first author’s Computers and Telematics MEng dissertation. The strategy proposed is based on a crowdsourcing camellia specimen informatio...

Este artigo apresenta os últimos desenvolvimentos do projeto de um sistema para reproduzir áudio binaural sem necessidade de auscultadores convencionais. O sistema utiliza altifalantes paramétricos e técnicas de beamforming digital, implementadas em FPGA, para produzir feixes áudio e controlar a sua direção em tempo real.

Previous findings have shown that humans can learn to localize with altered auditory space cues. Here we analyze such learning processes and their effects up to one month on both localization accuracy and sound externalization. Subjects were trained and retested, focusing on the effects of stimulus type in learning, stimulus type in localization, s...

This paper describes a software package for auralisation in inter- active virtual reality environments. Its purpose is to reproduce, in real time, the 3D soundfield within a virtual room where listener and sound sources can be moved freely. Output sound is presented binaurally using headphones. Auralisation is based on geometric acoustic models com...

Este artigo descreve uma implementação em software para auralização de ambientes de realidade virtual interactivos. A finalidade é reproduzir, em tempo real, o campo sonoro tridimensional numa sala virtual onde ouvinte e fontes sonoras se podem movimentar livremente. O som é apresentado de forma binaural, usando auscultadores. A auralização é basea...

Este artigo apresenta um sistema de áudio binaural que utiliza altifalantes paramétricos recorrendo a beamforming para direcionar cada feixe sonoro para o ouvido respetivo. A posição dos ouvidos é determinada em tempo real por tracking da face do ouvinte através de uma aplicação de visão por computador.

The perception of sound distance has been sparsely studied so far. It is assumed to depend on familiar loudness, reverberation, sound spectrum, and parallax, but most of these factors have never been carefully addressed. Reverberation has been mostly analyzed in terms of ratio between direct and indirect sound, and total duration. Here we were inte...

This paper presents a real-time audio augmented reality system that enables users to experience binaural audio according to their position and head orientation relative to virtual audio sources placed at points of interest in the room. The main goal is to create the illusion that an object acts as a sound source. For this purpose, the proposed syst...

Respiratory physiotherapy is a gold standard intervention for chronic respiratory conditions. However, its application in acute respiratory diseases (e.g., LRTI) is not well established. The objective and reliable measurement of adventitious lung sounds (ALS), such as wheezes, has the potential to contribute to respiratory physiotherapy evidence ba...

Four crackle detection algorithms were implemented based on selected techniques proposed in the literature. The algorithms were tested on a set of lung sounds and their performance was assessed in terms of sensitivity (SE), accuracy (PPV) and their harmonic mean (F index). The reference annotation data for calculating these indices were obtained th...

Significant research efforts have been dedicated to the automatic detection of adventitious lung sounds, using, for this purpose, different algorithms. The validation of these algorithms is based on the comparison of their results with reference annotations and therefore requires the development of user-friendly annotation software. This paper pres...

Auralization is a powerful tool to increase the realism and sense of immersion in Virtual Reality environments. The Head Related Transfer Function (HRTF) filters commonly used for auralization are non-individualized, as obtaining individualized HRTFs poses very serious practical difficulties. It is therefore extremely important to understand to wha...

Auralization is a powerful tool to increase the realism and sense of immersion in Virtual Reality environments. The Head Related Transfer Function (HRTF) filters commonly used for auralization are non-individualized, as obtaining individualized HRTFs poses very serious practical difficulties. It is therefore extremely important to understand to wha...

Auralisations with HRTFs are an innovative tool for the reproduction of acoustic space. Their broad applicability depends on the use of non-individualised models, but little is known on how humans adapt to these sounds. Previous findings have shown that simple exposure to non-individualised virtual sounds did not provide a quick adaptation, but tha...

A aplicação CapView utiliza um algoritmo de classificação baseado em SVM (Support Vector Machines) para automatizar a segmentação topográfica de vídeos do trato intestinal obtidos por cápsula endoscópica. Este trabalho explora a aplicação de processadores gráficos (GPU) para paralelização desse algoritmo. Após uma etapa de otimização da versão sequ...

A novel application-specific hardware (ASH) unit was designed to form the building block of the Meshotron - a parallelisation network for three-dimensional (3D) digital wave guide-mesh (DWM) room acoustic models. The rectangular mesh topology was elected. This ASH unit was tested using professional hardware simulation tools, assuming 32-bit integer...

Auralization is a powerful tool to increase the realism and sense of immersion in Virtual Reality environments. The Head Related Transfer Function (HRTF) filters commonly used for auralization are non-individualized, as obtaining individualized HRTFs poses very serious practical difficulties. It is therefore extremely important to understand to wha...

Detailed and convincing walkthrough auralizations of virtual rooms requires much processing capability. One method of reducing this requirement is to pre-calculate a data-set of room impulse responses (RIR) at locations throughout the space. Processing resources may then focus on RIR interpolation and convolution using the dataset as the virtual li...

This paper presents the project of a computing network - the "Meshotron" - specifically designed for large-scale parallelisation of three-dimensional Digital Waveguide Mesh (3D DWM) room acoustic models. It discusses the motivation of the project, its advantages and the architecture envisaged for the application-specific hardware (ASH) units to for...

In the Theremin, the performer’s hand movements, detected by two antennas, control the pitch and volume of the generated sound. The TheremUS builds on this concept by using ultrasonic sensing for hand position detection and processing all signals digitally, a distinct advantage in terms of versatility. Not only can different sound synthesis algorit...

This paper presents preliminary results on the development of a 3D audiovisual model of the Anta Pintada (painted dolmen) of Antelas, a Neolithic chamber tomb located in Oliveira de Frades and listed as Portuguese national monument. The final aim of the project is to create a highly accurate Virtual Reality (VR) model of this unique archaeological...

Room acoustic simulation using digital waveguide modeling requires three-dimensional waveguide meshes in order to represent fully the acoustic properties of the space. This paper presents a systematic analysis of four mesh topologies suggested in the literature: rectilinear, tetrahedral, cubic close-packed and octahedral. These mesh structures are...

After briefly discussing the accuracy requirements of various auralisation system applications, the paper reviews the principles of digital-waveguide modelling and its application to 3D acoustic simulation for accurate auralisation. A formula is derived for the computation time of a regular rectilinear mesh model, assuming lossless propagation. A s...