Indirect structural health monitoring (iSHM) of transport infrastructure in the digital age

Workshop reportCopyright © Joint Research Centre (European Commission). The existing European motorway infrastructure network is prone to ageing and subject to natural events (e.g. climate change) and hazards (e.g. earthquakes), necessitating immediate actions for its maintenance and safety. Within this context, the structural health monitoring (SHM) framework allows a quantitative assessment of the structural integrity, serviceability and performance, facilitating better-informed decisions for the management of the existing infrastructure. The European Commission Joint Research Centre (JRC) established the exploratory research project MITICA (Monitoring Transport Infrastructures with Connected and Automated vehicles) to investigate the opportunity to use novel methods for infrastructure motoring, aiming at the efficient maintenance of the European aging road infrastructure. This report summarizes the discussion and the outcomes of a workshop held at the JRC in Ispra (Italy) on June 6-7 2022, as part of the MITICA project. Considering the EU priority “A Europe fit for the digital age”, the workshop was dedicated to SHM and its application to civil infrastructure, focusing on innovative indirect structural health monitoring (iSHM) approaches that rely on the vehicle-bridge interaction and the deployment of sensor-equipped vehicles for the monitoring of the existing bridge infrastructure. The report aims to become a reference document in the area of iSHM using passing vehicles, for both scholars and policy makers

Speech level in rooms with very low and very high reverberation

Numerous studies have dealt so far with changing in speech production for talkers due to different acoustic environments, but mostly have been focused on the effect of noise or distance from the listeners and not many on the effect of reverberation. Reverberation has an influence on the voice production, supporting talkers as well as increasing speech level towards an audience. In spite of its positive effects, excessive reverberation influences talkers making them use erroneous vocal behaviors, which may be cause of discomfort and a risk for vocal health, especially in the case of prolonged speech, as for teachers in classrooms. The present work explores the differences in sound pressure level and sound power level of running speech from several speakers, in semi-anechoic and reverberant rooms. Two types of spontaneous speech, a free monologue and the description of a map, have been addressed with a communicative intent to a listener seated at a fixed distance of 6 m. Measurements have been carried out with a headworn microphone and with Voice Care, a voice dosimeter based on a contact microphone. Subjective impressions were caught after subjects have spoken in the two rooms

Speech level parameters in very low and excessive reverberation measured with a contact-sensor-based device and a headworn microphone

This work deals with the effect of very low and excessive reverberation on speech sound pressure levels. Measurements were carried out in a semi-anechoic and reverberant room using a contact-sensor-based device fixed at the base of the neck and a headworn microphone placed at 2.5 cm from the speaker’s mouth. Speakers produced short monologues and also described a map with the intent of correctly explaining directions to a listener 6 m away. A significant increase of about 2 dB in mean, equivalent, and mode speech levels in semi-anechoic compared to reverberant room was on average observed for the map description from recordings with the contact device, thus, highlighting an increased vocal intensity in dead rooms when the speech task had a communicative intent. Such reliable results were not found with the headworn microphone because speech levels were affected by noise recorded in the pauses. Particularly, the 30 ms logging interval brought to more severe errors in mode and mean speech levels compared to 1 s. When the pauses were removed and a logging interval of 30 ms was adopted, results were more consistent with those obtained with the contact sensor, but level differences between the two rooms still remained not significant

Speech level in rooms with very low and very high reverberation

Numerous studies have dealt so far with changing in speech production for talkers due to different acoustic environments, but mostly have been focused on the effect of noise or distance from the listeners and not many on the effect of reverberation. Reverberation has an influence on the voice production, supporting talkers as well as increasing speech level towards an audience. In spite of its positive effects, excessive reverberation influences talkers making them use erroneous vocal behaviors, which may be cause of discomfort and a risk for vocal health, especially in the case of prolonged speech, as for teachers in classrooms. The present work explores the differences in sound pressure level and sound power level of running speech from several speakers, in semi-anechoic and reverberant rooms. Two types of spontaneous speech, a free monologue and the description of a map, have been addressed with a communicative intent to a listener seated at a fixed distance of 6 m. Measurements have been carried out with a headworn microphone and with Voice Care, a voice dosimeter based on a contact microphone. Subjective impressions were caught after subjects have spoken in the two rooms

Effetti di scarsa ed eccessiva riverberazione sul parlato continuo

Numerosi studi hanno affrontato il tema degli effetti di diversi ambienti acustici sul parlato continuo, ma la maggior parte sono stati per lo più focalizzati sugli effetti del rumore o della distanza tra parlator e ascoltatore, e solo pochi hanno considerato l'effetto della riverberazione dell’ambiente. La riverberazione ha influenza sulla produzione vocale, supportando il parlatore e aumentando il livello sonoro per gli ascoltatori. Nonostante gli effetti positivi, l’eccessiva riverberazione può influenzare negativamente il parlatore portandolo ad un comportamento vocale errato, che può essere causa di disagio e rischio per la salute vocale, soprattutto nel caso di parlato prolungato. Il presente lavoro riporta le differenze di livello medio di pressione sonora e di frequenza fondamentale relativi ad un campione di parlato continuo della durata di 4 o 5 minuti, prelevati in una camera semi-anecoica e una camera riverberante. Sono stati considerati due tipi di parlato spontaneo, un monologo libero e la descrizione di una mappa, con un intento comunicativo tra un parlatore ed un ascoltatore ad una distanza fissa di 6 m. Le misurazioni sono state effettuate con un microfono da guancia per 57 soggetti e con il dispositivo Voice Care, basato su un microfono a contatto fissato sulla fossetta del giugulo, per 38 soggetti. Tutti i soggetti erano al di sotto dei trent’anni e normoudenti. L’incertezza nella stima dei valori di SPL è stata valutata per i diversi metodi di misura e sono state raccolte le impressioni soggettive dei soggetti che hanno parlato nelle due camere