An Approach to Frequency Selectivity in an Urban Environment by Means of Multi-Path Acoustic Channel Analysis
The improvement of quality of life in the framework of the smart city paradigm cannot be limited to a set of objective measures carried out over several critical parameters (e.g., noise or air pollution). Noise disturbances depend not only on the equivalent level <i>L<sub>Aeq</sub>...
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| Format: | Article |
| Language: | English |
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MDPI AG
2019-06-01
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| Series: | Sensors |
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| Online Access: | https://www.mdpi.com/1424-8220/19/12/2793 |
| _version_ | 1811187342155710464 |
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| author | Pau Bergadà Rosa Ma Alsina-Pagès |
| author_facet | Pau Bergadà Rosa Ma Alsina-Pagès |
| author_sort | Pau Bergadà |
| collection | DOAJ |
| description | The improvement of quality of life in the framework of the smart city paradigm cannot be limited to a set of objective measures carried out over several critical parameters (e.g., noise or air pollution). Noise disturbances depend not only on the equivalent level <i>L<sub>Aeq</sub></i> measured, but also on the spectral distribution of the sounds perceived by people. Propagation modelling to conduct auralization can be done either with geometrical acoustics or with wave-based methods, given the fact that urban environments are acoustically complex scenarios. In this work, we present a first analysis of the acoustic spectral distribution of street noise, based on the frequency selectivity of the urban outdoor channel and its corresponding coherence bandwidth. The analysis was conducted in the framework of the data collected in the Milan pilotWASN of the DYNAMAP LIFE project, with the use of three simulated acoustic impulse responses. The results show the clear influence of the evaluated coherence bandwidth of each of the simulated channels over real-life acoustic samples, which leads us to the conclusion that all raw acoustic samples have to be considered as wide-band. The results also depict a dependence of accumulated energy at the receiver with the coherence bandwidth of the channel. We conclude that, the higher the delay spread of the channel, the narrower the coherence bandwidth and the higher the distortion suffered by acoustic signals. Moreover, the accumulated energy of the received signal along the frequency axis tends to differ from the accumulated energy of the transmitted signal when facing narrow coherence bandwidth channels; whereas the accumulated energy along the time axis diverges from the accumulated transmitted energy when facing wide coherence bandwidth channels. |
| first_indexed | 2024-04-11T14:01:37Z |
| format | Article |
| id | doaj.art-8c272908f19d48c3821d52a367a2beb5 |
| institution | Directory Open Access Journal |
| issn | 1424-8220 |
| language | English |
| last_indexed | 2024-04-11T14:01:37Z |
| publishDate | 2019-06-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Sensors |
| spelling | doaj.art-8c272908f19d48c3821d52a367a2beb52022-12-22T04:20:07ZengMDPI AGSensors1424-82202019-06-011912279310.3390/s19122793s19122793An Approach to Frequency Selectivity in an Urban Environment by Means of Multi-Path Acoustic Channel AnalysisPau Bergadà0Rosa Ma Alsina-Pagès1Grup de recerca en Tecnologies Mèdia (GTM), La Salle, Universitat Ramon Llull, c/Quatre Camins, 30, 08022 Barcelona, SpainGrup de recerca en Tecnologies Mèdia (GTM), La Salle, Universitat Ramon Llull, c/Quatre Camins, 30, 08022 Barcelona, SpainThe improvement of quality of life in the framework of the smart city paradigm cannot be limited to a set of objective measures carried out over several critical parameters (e.g., noise or air pollution). Noise disturbances depend not only on the equivalent level <i>L<sub>Aeq</sub></i> measured, but also on the spectral distribution of the sounds perceived by people. Propagation modelling to conduct auralization can be done either with geometrical acoustics or with wave-based methods, given the fact that urban environments are acoustically complex scenarios. In this work, we present a first analysis of the acoustic spectral distribution of street noise, based on the frequency selectivity of the urban outdoor channel and its corresponding coherence bandwidth. The analysis was conducted in the framework of the data collected in the Milan pilotWASN of the DYNAMAP LIFE project, with the use of three simulated acoustic impulse responses. The results show the clear influence of the evaluated coherence bandwidth of each of the simulated channels over real-life acoustic samples, which leads us to the conclusion that all raw acoustic samples have to be considered as wide-band. The results also depict a dependence of accumulated energy at the receiver with the coherence bandwidth of the channel. We conclude that, the higher the delay spread of the channel, the narrower the coherence bandwidth and the higher the distortion suffered by acoustic signals. Moreover, the accumulated energy of the received signal along the frequency axis tends to differ from the accumulated energy of the transmitted signal when facing narrow coherence bandwidth channels; whereas the accumulated energy along the time axis diverges from the accumulated transmitted energy when facing wide coherence bandwidth channels.https://www.mdpi.com/1424-8220/19/12/2793noisepropagation modelfrequency selectivityacoustic channelwidebandauralizationsmartcityimpulse responsecoherence bandwidthwireless acoustic sensor network |
| spellingShingle | Pau Bergadà Rosa Ma Alsina-Pagès An Approach to Frequency Selectivity in an Urban Environment by Means of Multi-Path Acoustic Channel Analysis Sensors noise propagation model frequency selectivity acoustic channel wideband auralization smartcity impulse response coherence bandwidth wireless acoustic sensor network |
| title | An Approach to Frequency Selectivity in an Urban Environment by Means of Multi-Path Acoustic Channel Analysis |
| title_full | An Approach to Frequency Selectivity in an Urban Environment by Means of Multi-Path Acoustic Channel Analysis |
| title_fullStr | An Approach to Frequency Selectivity in an Urban Environment by Means of Multi-Path Acoustic Channel Analysis |
| title_full_unstemmed | An Approach to Frequency Selectivity in an Urban Environment by Means of Multi-Path Acoustic Channel Analysis |
| title_short | An Approach to Frequency Selectivity in an Urban Environment by Means of Multi-Path Acoustic Channel Analysis |
| title_sort | approach to frequency selectivity in an urban environment by means of multi path acoustic channel analysis |
| topic | noise propagation model frequency selectivity acoustic channel wideband auralization smartcity impulse response coherence bandwidth wireless acoustic sensor network |
| url | https://www.mdpi.com/1424-8220/19/12/2793 |
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