Marc Freixes

Dr. Marc Freixes

HER - Human Environment Research, La Salle Campus Barcelona, Ramon Llull University, Barcelona, Catalonia, Spain
orcid

Research Focus & Metrics

Academic Career Length

22Years (2005-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

View All Publications
21 May 2021 in Sustainability
Verified
Journal Article
Open access
PDF file
Ferran OrgaFerran Orga
Ferran Orga
Andrew MitchellAndrew Mitchell
Andrew Mitchell
Marc FreixesMarc Freixes
Marc Freixes
Francesco AlettaFrancesco Aletta
Francesco Aletta
Rosa Ma Alsina-PagèsRosa Ma Alsina-Pagès
Rosa Ma Alsina-Pagès
MFMaria Foraster
Maria Foraster
The recent development and deployment of Wireless Acoustic Sensor Networks (WASN) present new ways to address urban acoustic challenges in a smart city context. A focus on improving quality of life forms the core of smart-city design paradigms and cannot be limited to simply measuring objective environmental factors, but should also consider the perceptual, psychological and health impacts on citizens. This study therefore makes use of short (1–2.7 s) recordings sourced from a WASN in Milan which were grouped into various environmental sound source types and given an annoyance rating via an online survey with N=100 participants. A multilevel psychoacoustic model was found to achieve an overall R2=0.64 which incorporates Sharpness as a fixed effect regardless of the sound source type and Roughness, Impulsiveness and Tonality as random effects whose coefficients vary depending on the sound source. These results present a promising step toward implementing an on-sensor annoyance model which incorporates psychoacoustic features and sound source type, and is ultimately not dependent on sound level.

25 October 2019 in Applied Sciences
Verified
Journal Article
Open access
PDF file
Marc FreixesMarc Freixes
Marc Freixes
MAMarc Arnela
Marc Arnela
JSJoan Claudi Socoró
Joan Claudi Socoró
Francesc Alías-PujolFrancesc Alías-Pujol
Francesc Alías-Pujol
OGOriol Guasch
Oriol Guasch
Articulatory speech synthesis has long been based on one-dimensional (1D) approaches. They assume plane wave propagation within the vocal tract and disregard higher order modes that typically appear above 5 kHz. However, such modes may be relevant in obtaining a more natural voice, especially for phonation types with significant high frequency energy (HFE) content. This work studies the contribution of the glottal source at high frequencies in the 3D numerical synthesis of vowels. The spoken vocal range is explored using an LF (Liljencrants–Fant) model enhanced with aspiration noise and controlled by the R d glottal shape parameter. The vowels [ɑ], [i], and [u] are generated with a finite element method (FEM) using realistic 3D vocal tract geometries obtained from magnetic resonance imaging (MRI), as well as simplified straight vocal tracts of a circular cross-sectional area. The symmetry of the latter prevents the onset of higher order modes. Thus, the comparison between realistic and simplified geometries enables us to analyse the influence of such modes. The simulations indicate that higher order modes may be perceptually relevant, particularly for tense phonations (lower R d values) and/or high fundamental frequency values, F 0 s. Conversely, vowels with a lax phonation and/or low F0s may result in inaudible HFE levels, especially if aspiration noise is not considered in the glottal source model.

11 March 2020 in Cities & Health
Verified
Journal Article
Closed access
Rosa Ma Alsina-PagèsRosa Ma Alsina-Pagès
Rosa Ma Alsina-Pagès
Marc FreixesMarc Freixes
Marc Freixes
FOFerran Orga
Ferran Orga
MFMaria Foraster
Maria Foraster
ALAlexandra Labairu-Trenchs
Alexandra Labairu-Trenchs
Noise is one of the main environmental pollutants and it is becoming a growing public health concern due to its impact on the quality of life in urban areas. In order to monitor critical locations, Wireless Acoustic Sensor Networks are being deployed, mainly in European and American cities. These networks focus primarily on measuring noise levels associated with road traffic. However, a number of different sounds are also present in urban areas and if our overall aim is to improve the quality of life of city inhabitants, then these additional sounds should be considered in accordance with the soundscape approach. This think piece proposes a step forward in the analysis of citizens’ perception of noise annoyance. We want to analyse the degree of annoyance caused by different sounds and study how this is related to psychoacoustic parameters. To this end, we propose to assess the acoustic environment by conducting perceptual tests on data gathered in a noise monitoring network. The proposed methodology is presented and discussed, and several open questions are posed to the research community.

14 November 2020 in Engineering Proceedings
Verified
Conference Paper
Open access
PDF file
Rosa Ma Alsina-PagèsRosa Ma Alsina-Pagès
Rosa Ma Alsina-Pagès
Ferran OrgaFerran Orga
Ferran Orga
RMRoger Mallol
Roger Mallol
Marc FreixesMarc Freixes
Marc Freixes
XBXavier Baño
Xavier Baño
MFMaria Foraster
Maria Foraster
In this project, we aim to study the effect that the lockdown due to the COVID-19 pandemic has caused on the perception of noise in Catalonia. In Sons al Balcó, the research activities cohabit with the dynamic collaboration with citizens and other stakeholders to create social and environmental impact, to widen awareness and design tools to improve citizenship development and empowerment. The initial scientific hypothesis is that the annoyance coming from outdoor noise, minimized by the lockdown effect, could be associated with better perception of the soundscape by people. Sons al Balcó allows validating this hypothesis in two different ways. On the one hand, by means of subjective questionnaires conducted to people living in pre-defined diverse acoustic areas (urban, suburban and rural environments), and on the other hand, by the use of objective measurements of the noise levels, and the study of the soundscape in these areas, using short pieces of video collected by citizens. For this purpose, we designed an on line test to be conducted by any citizen aiming to contribute to this wide study for all the territory of Catalonia, both from rural areas and from cities. A communication campaign was conducted to reach a significant participation. During the lockdown, more than 350 questionnaires and videos were collected, and a first map of the soundscape of the confinement in Catalonia was depicted.

1 January 2021 in Noise Mapping
Verified
Journal Article
Open access
PDF file
Rosa Ma Alsina-PagèsRosa Ma Alsina-Pagès
Rosa Ma Alsina-Pagès
GGGerardo José Ginovart-Panisello
Gerardo José Ginovart-Panisello
Marc FreixesMarc Freixes
Marc Freixes
ARAntonella Radicchi
Antonella Radicchi
The Poblenou Superblock, in Barcelona, is a crucial element in the development of the new city-planning within the framework of the Superblock (Superilles) concept, whose principal aim is to recover the cultural, economic and social exchanges once produced in streets and squares. People living in urban areas need a lower traffic density, more green spaces and cleaner air in order to restore the previous uses of public spaces in their day-today lives. The urban actions conducted at this Superblock to change its uses were completed about 3 years ago, and neighbours and workers have already taken over the new spaces. In an interdisciplinary work on urban planning and acoustics, we detail the preliminary results of the acoustic events found in the recordings in a soundwalk in the heart of the Poblenou Superblock. Fifteen people evaluate and record sound fragments with the Hush City App application, in order to establish comparisons between the different points of the route, observe the spaces arranged for people and perceive the soundscape. Meanwhile, several acoustic technicians record 5-min long audios in the different stops designed for the soundwalk. The points chosen to make the recordings are very different from each other, some of them in the middle of gardens and others are on pacific streets and finally, we also wanted to include Superblock borders where the traffic is still very present. The results of our study were promising and have encouraged us to further investigate acoustics events in superblocks and include all the perceptual information provided by the Hush City App.

17 September 2022 in Sensors
Verified
Journal Article
Open access
PDF file
SCSelene Caro-Via
Selene Caro-Via
Ester Vidaña-VilaEster Vidaña-Vila
Ester Vidaña-Vila
GGGerardo José Ginovart
Gerardo José Ginovart
CMCarme Martínez-Suquía
Carme Martínez-Suquía
Marc FreixesMarc Freixes
Marc Freixes
Rosa Ma Alsina-PagèsRosa Ma Alsina-Pagès
Rosa Ma Alsina-Pagès
This work presents the design of a wireless acoustic sensor network (WASN) that monitors indoor spaces. The proposed network would enable the acquisition of valuable information on the behavior of the inhabitants of the space. This WASN has been conceived to work in any type of indoor environment, including houses, hospitals, universities or even libraries, where the tracking of people can give relevant insight, with a focus on ambient assisted living environments. The proposed WASN has several priorities and differences compared to the literature: (i) presenting a low-cost flexible sensor able to monitor wide indoor areas; (ii) balance between acoustic quality and microphone cost; and (iii) good communication between nodes to increase the connectivity coverage. A potential application of the proposed network could be the generation of a sound map of a certain location (house, university, offices, etc.) or, in the future, the acoustic detection of events, giving information about the behavior of the inhabitants of the place under study. Each node of the network comprises an omnidirectional microphone and a computation unit, which processes acoustic information locally following the edge-computing paradigm to avoid sending raw data to a cloud server, mainly for privacy and connectivity purposes. Moreover, this work explores the placement of acoustic sensors in a real scenario, following acoustic coverage criteria. The proposed network aims to encourage the use of real-time non-invasive devices to obtain behavioral and environmental information, in order to take decisions in real-time with the minimum intrusiveness in the location under study.