{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,12,6]],"date-time":"2025-12-06T16:42:55Z","timestamp":1765039375679,"version":"build-2065373602"},"reference-count":56,"publisher":"MDPI AG","issue":"12","license":[{"start":{"date-parts":[[2017,11,29]],"date-time":"2017-11-29T00:00:00Z","timestamp":1511913600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>The spreading of urban areas and the growth of human population worldwide raise societal and environmental concerns. To better address these concerns, the monitoring of the acoustic environment in urban as well as rural or wilderness areas is an important matter. Building on the recent development of low cost hardware acoustic sensors, we propose in this paper to consider a sensor grid approach to tackle this issue. In this kind of approach, the crucial question is the nature of the data that are transmitted from the sensors to the processing and archival servers. To this end, we propose an efficient audio coding scheme based on third octave band spectral representation that allows: (1) the estimation of standard acoustic indicators; and (2) the recognition of acoustic events at state-of-the-art performance rate. The former is useful to provide quantitative information about the acoustic environment, while the latter is useful to gather qualitative information and build perceptually motivated indicators using for example the emergence of a given sound source. The coding scheme is also demonstrated to transmit spectrally encoded data that, reverted to the time domain using state-of-the-art techniques, are not intelligible, thus protecting the privacy of citizens.<\/jats:p>","DOI":"10.3390\/s17122758","type":"journal-article","created":{"date-parts":[[2017,11,30]],"date-time":"2017-11-30T03:15:15Z","timestamp":1512011715000},"page":"2758","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":12,"title":["An Efficient Audio Coding Scheme for Quantitative and Qualitative Large Scale Acoustic Monitoring Using the Sensor Grid Approach"],"prefix":"10.3390","volume":"17","author":[{"given":"F\u00e9lix","family":"Gontier","sequence":"first","affiliation":[{"name":"LS2N, UMR 6004, \u00c9cole Centrale de Nantes, 44300 Nantes, France"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Mathieu","family":"Lagrange","sequence":"additional","affiliation":[{"name":"LS2N, UMR 6004, \u00c9cole Centrale de Nantes, 44300 Nantes, France"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8834-4251","authenticated-orcid":false,"given":"Pierre","family":"Aumond","sequence":"additional","affiliation":[{"name":"LAE, AME, IFSTTAR, 44340 Bouguenais, France"},{"name":"ETIS, UMR 8051, Universit\u00e9 Paris Seine, Universit\u00e9 de Cergy-Pontoise, ENSEA, CNRS, 95000 Cergy-Pontoise, France"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Arnaud","family":"Can","sequence":"additional","affiliation":[{"name":"LAE, AME, IFSTTAR, 44340 Bouguenais, France"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Catherine","family":"Lavandier","sequence":"additional","affiliation":[{"name":"ETIS, UMR 8051, Universit\u00e9 Paris Seine, Universit\u00e9 de Cergy-Pontoise, ENSEA, CNRS, 95000 Cergy-Pontoise, France"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2017,11,29]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"207","DOI":"10.1016\/j.apacoust.2016.06.010","article-title":"The implementation of low-cost urban acoustic monitoring devices","volume":"117","author":"Mydlarz","year":"2017","journal-title":"Appl. Acoust."},{"key":"ref_2","first-page":"3808","article-title":"Characterization of urban sound environments using a comprehensive approach combining open data, measurements, and modeling","volume":"141","author":"Picaut","year":"2017","journal-title":"J. Acoust. Soc. Am."},{"key":"ref_3","unstructured":"Lim, H., Teo, Y., Mukherjee, P., Lam, V., Wong, W., and See, S. (2005, January 17). Sensor grid: Integration of wireless sensor networks and the grid. Proceedings of the 2005 30th Anniversary IEEE Conference on Local Computer Networks, Sydney, Australia."},{"key":"ref_4","first-page":"24","article-title":"SensorGrid: Integrating sensor networks and grid computing","volume":"29","author":"Tham","year":"2005","journal-title":"CSI Commun."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1016\/j.apacoust.2015.03.020","article-title":"Relationship between objective acoustic indices and subjective assessments for the quality of soundscapes","volume":"97","year":"2015","journal-title":"Appl. Acoust."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"240","DOI":"10.1016\/j.apacoust.2011.01.004","article-title":"Soundscape categorization on the basis of objective acoustical parameters","volume":"74","author":"Rychtarikova","year":"2013","journal-title":"Appl. Acoust."},{"key":"ref_7","unstructured":"Can, A., Aumond, P., Michel, S., De Coensel, B., Ribeiro, C., Botteldooren, D., and Lavandier, C. (2016, January 21\u201324). Comparison of noise indicators in an urban context. Proceedings of the 45th International Congress and Exposition on Noise Control Engineering, Hamburg, Germany."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"208","DOI":"10.1121\/1.4904555","article-title":"Describing and classifying urban sound environments with a relevant set of physical indicators","volume":"137","author":"Can","year":"2015","journal-title":"J. Acoust. Soc. Am."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"813","DOI":"10.1121\/1.4807809","article-title":"Measurements of acoustic environments for urban soundscapes: Choice of homogeneous periods, optimization of durations, and selection of indicators","volume":"134","author":"Brocolini","year":"2013","journal-title":"J. Acoust. Soc. Am."},{"key":"ref_10","unstructured":"Nilsson, M., Botteldooren, D., and De Coensel, B. (2007, January 2\u20137). Acoustic indicators of soundscape quality and noise annoyance in outdoor urban areas. Proceedings of the 19th International Congress on Acoustics, Madrid, Spain."},{"key":"ref_11","first-page":"912","article-title":"The contribution of sound source characteristics in the assessment of urban soundscapes","volume":"92","author":"Lavandier","year":"2006","journal-title":"Acta Acust. United Acust."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"430","DOI":"10.3813\/AAA.919073","article-title":"Modeling soundscape pleasantness using perceptual assessments and acoustic measurements along paths in urban context","volume":"103","author":"Aumond","year":"2017","journal-title":"Acta Acust. United Acust."},{"key":"ref_13","doi-asserted-by":"crossref","unstructured":"Alsina-Pag\u00e8s, R., Hernandez-Jayo, U., Al\u00edas, F., and Angulo, I. (2016). Design of a mobile low-cost sensor network using urban buses for real-time ubiquitous noise monitoring. Sensors, 17.","DOI":"10.3390\/s17010057"},{"key":"ref_14","doi-asserted-by":"crossref","unstructured":"Al\u00edas, F., and Socor\u00f3, J. (2017). Description of anomalous noise events for reliable dynamic traffic noise mapping in real-life urban and suburban soundscapes. Appl. Sci., 7.","DOI":"10.3390\/app7020146"},{"key":"ref_15","unstructured":"Gloaguen, J.R., Can, A., Lagrange, M., and Petiot, J.F. (2016, January 3). Estimating traffic noise levels using acoustic monitoring: A preliminary study. Proceedings of the Detection and Classification of Acoustic Scenes and Events (DCASE 2016), Budapest, Hungary."},{"key":"ref_16","unstructured":"Defr\u00e9ville, B., Pachet, F., Rosin, C., and Roy, P. (2006, January 20\u201323). Automatic recognition of urban sound sources. Proceedings of the Audio Engineering Society Convention 120, Paris, France."},{"key":"ref_17","unstructured":"Mydlarz, C., Shamoon, C., Baglione, M., and Pimpinella, M. (June, January 31). The design and calibration of low cost urban acoustic sensing devices. Proceedings of the EuroNoise 2015, Maastricht, The Netherlands."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"60","DOI":"10.1109\/93.388209","article-title":"A tutorial on MPEG\/audio compression","volume":"2","author":"Pan","year":"1995","journal-title":"IEEE Multimedia"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"225","DOI":"10.1016\/S0389-4304(99)00090-9","article-title":"The impact of sound quality on annoyance caused by road traffc noise: An influence of frequency spectra on annoyance","volume":"21","author":"Ishiyama","year":"2000","journal-title":"JSAE Rev."},{"key":"ref_20","first-page":"181","article-title":"Speech recognition by machine, a review","volume":"6","author":"Anusuya","year":"2009","journal-title":"Int. J. Comput. Sci. Inf. Secur."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"293","DOI":"10.1109\/TSA.2002.800560","article-title":"Automatic musical genre classification of audio signals","volume":"10","author":"Tzanztakis","year":"2002","journal-title":"IEEE Trans. Speech Audio Process."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"69","DOI":"10.1016\/j.dsp.2014.05.003","article-title":"Universal background modeling for acoustic surveillance of urban traffic","volume":"31","author":"Ntalampiras","year":"2014","journal-title":"Digit. Signal Process."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"881","DOI":"10.1121\/1.2750160","article-title":"The bag-of-frames approach to audio pattern recognition: A sufficient model for urban soundscapes but not for polyphonic music","volume":"122","author":"Aucouturier","year":"2007","journal-title":"J. Acoust. Soc. Am."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"22","DOI":"10.1016\/j.patrec.2015.06.026","article-title":"Reliable detection of audio events in highly noisy environments","volume":"65","author":"Foggia","year":"2015","journal-title":"Pattern Recognit. Lett."},{"key":"ref_25","unstructured":"Kumar, A., and Raj, B. (2017, November 28). Features and Kernels for Audio Event Recognition. Available online: https:\/\/arxiv.org\/abs\/1607.05765."},{"key":"ref_26","unstructured":"Radhakrishnan, R., Divakaran, A., and Smaragdis, P. (2005, January 16). Audio analysis for surveillance applications. Proceedings of the IEEE Workshop on Applications of Signal Processing to Audio and Acoustics, New Paltz, NY, USA."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"279","DOI":"10.1109\/LSP.2017.2657381","article-title":"Deep convolutional neural networks and data augmentation for environmental sound classification","volume":"24","author":"Salamon","year":"2017","journal-title":"IEEE Signal Process. Lett."},{"key":"ref_28","doi-asserted-by":"crossref","unstructured":"Piczak, K. (2015, January 17\u201320). Environmental sound classification with convolutional neural networks. Proceedings of the IEEE 25th International Workshop on Machine Learning for Signal Processing, Boston, MA, USA.","DOI":"10.1109\/MLSP.2015.7324337"},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"57","DOI":"10.1016\/j.ins.2013.04.014","article-title":"Very short time environmental sound classification based on spectrogram pattern matching","volume":"243","author":"Khunarsal","year":"2013","journal-title":"Inf. Sci."},{"key":"ref_30","unstructured":"Couvreur, L., and Laniray, M. (2004, January 22\u201325). Automatic noise recognition in urban environments based on artificial neural networks and hidden markov models. Proceedings of the 33rd International Congress and Exposition on Noise Control Engineering, Prague, Czech Republic."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"1026","DOI":"10.1109\/TSA.2005.857575","article-title":"A flexible framewok for key audio effects detection and auditory context inference","volume":"14","author":"Cai","year":"2006","journal-title":"IEEE Trans. Audio Speech Lang. Process."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"1142","DOI":"10.1109\/TASL.2009.2017438","article-title":"Environmental sound recognition with time-frequency audio features","volume":"17","author":"Chu","year":"2009","journal-title":"IEEE Trans. Audio Speech Lang. Process."},{"key":"ref_33","doi-asserted-by":"crossref","unstructured":"Baug\u00e9, C., Lagrange, M., And\u00e9n, J., and Mallat, S. (2013, January 26\u201331). Representing environmental sounds using the separable scattering transform. Proceedings of the 2013 IEEE International Conference on Acoustics, Speech and Signal Processing, Vancouver, BC, Canada.","DOI":"10.1109\/ICASSP.2013.6639358"},{"key":"ref_34","unstructured":"Salamon, J., and Bello, J. (September, January 31). Feature learning with deep scattering for urban sound analysis. Proceedings of the 23rd European Signal Processing Conference, Nice, France."},{"key":"ref_35","doi-asserted-by":"crossref","unstructured":"Salamon, J., and Bello, J. (2015, January 19\u201324). Unsupervised feature learning for urban sound classification. Proceedings of the 2015 IEEE International Conference on Acoustics, Speech and Signal Processing, Brisbane, Australia.","DOI":"10.1109\/ICASSP.2015.7177954"},{"key":"ref_36","first-page":"686","article-title":"Acoustic detection of human activities in natural environments","volume":"60","author":"Ntalampiras","year":"2012","journal-title":"J. Audio Eng. Soc."},{"key":"ref_37","doi-asserted-by":"crossref","unstructured":"Chachada, S., and Kuo, C. (November, January 29). Environmental sound recognition: A survey. Proceedings of the 2013 Asia-Pacific Signal and Information Processing Association Annual Summit and Conference, Kaohsiung, Taiwan.","DOI":"10.1109\/APSIPA.2013.6694338"},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"791","DOI":"10.1121\/1.4807804","article-title":"Application of a methodology for categorizing and differentiating urban soundscapes using acoustical descriptors and semantic-differential attributes","volume":"134","author":"Torija","year":"2013","journal-title":"J. Acoust. Soc. Am."},{"key":"ref_39","doi-asserted-by":"crossref","unstructured":"Davis, S. (1986, January 7\u201311). Octave and fractional-octave band digital filtering based on the proposed ANSI standard. Proceedings of the 1986 IEEE International Conference on Acoustics, Speech and Signal Processing, Tokyo, Japan.","DOI":"10.1109\/ICASSP.1986.1168968"},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"884","DOI":"10.1121\/1.3273888","article-title":"Orthogonal-like fractional-octave-band filters","volume":"127","author":"Antoni","year":"2010","journal-title":"J. Acoust. Soc. Am."},{"key":"ref_41","unstructured":"(1993). ANSI S1.1-1986, (ASA 65-1986)\u2014Specifications for Octave-Band and Fractional-Octave-Band Analog and Digital Filters, ANSI."},{"key":"ref_42","unstructured":"(2014). IEC 61260-1:2014 \u2014Electroacoustics\u2014Octave-Band and Fractional-Octave-Band Filters\u2013Part 1: Specifications, IEC."},{"key":"ref_43","unstructured":"Couvreur, C. (2017, May 15). Implementation of a One-Third-Octave Filter Bank in Matlab. Available online: http:\/\/citeseer.ist.psu.edu\/24150.html."},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"1098","DOI":"10.1109\/JRPROC.1952.273898","article-title":"A method for the construction of minimum-redundancy codes","volume":"40","author":"Huffman","year":"1952","journal-title":"Proc. IRE"},{"key":"ref_45","unstructured":"Berzborn, M., Bomhardt, R., Klein, J., Richter, J.G., and Vorl\u00e4nder, M. (2017, January 6\u20139). The ITA-Toolbox: An open source MATLAB toolbox for acoustic measurements and signal processing. Proceedings of the 43th Annual German Congress on Acoustics, Kiel, Germany."},{"key":"ref_46","doi-asserted-by":"crossref","unstructured":"Salamon, J., Jacoby, C., and Bello, J. (2014, January 3\u20137). A dataset and taxonomy for urban sound research. Proceedings of the 22nd ACM international conference on Multimedia, Orlando, FL, USA.","DOI":"10.1145\/2647868.2655045"},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"185","DOI":"10.1109\/LSP.2013.2237902","article-title":"A novel holistic modeling acoustic approach for generalized sound recognition","volume":"20","author":"Ntalampiras","year":"2013","journal-title":"IEEE Signal Process. Lett."},{"key":"ref_48","unstructured":"Ellis, D. (2017, March 06). PLP and RASTA (and MFCC, and Inversion) in Matlab. Available online: http:\/\/www.ee.columbia.edu\/ ~dpwe\/resources\/matlab\/rastamat\/."},{"key":"ref_49","unstructured":"Baldwin, J., and French, P. (1990). Forensic Phonetics, Pinter Publishers."},{"key":"ref_50","doi-asserted-by":"crossref","first-page":"205","DOI":"10.1016\/S0167-6393(99)00079-5","article-title":"Forensic voice identification in France","volume":"31","year":"2000","journal-title":"Speech Commun."},{"key":"ref_51","doi-asserted-by":"crossref","unstructured":"Kuwabara, H. (1996, January 3\u20136). Acoustic properties of phonemes in continuous speech for different speaking rate. Proceedings of the Fourth International Conference on Spoken Language (ICSLP 96), Philadelphia, PA, USA.","DOI":"10.21437\/ICSLP.1996-611"},{"key":"ref_52","doi-asserted-by":"crossref","first-page":"367","DOI":"10.1098\/rstb.1992.0070","article-title":"Temporal information in speech: Acoustic, auditory and linguistic aspects","volume":"336","author":"Rosen","year":"1992","journal-title":"Philos. Trans. R. Soc. Lond. B Biol. Sci."},{"key":"ref_53","unstructured":"(2003). ITU-T P.835: Subjective Test Methodology for Evaluating Speech Communication Systems That Include Noise Suppression Algorithm, ITU."},{"key":"ref_54","doi-asserted-by":"crossref","unstructured":"Ntalampiras, S., Ganchev, T., and Potamitis, I. (2008, January 15\u201319). Objective comparison of speech enhancement algorithms under real world conditions. Proceedings of the 1st International Conference on PErvasive Technologies Related to Assistive Environments, Athens, Greece.","DOI":"10.1145\/1389586.1389627"},{"key":"ref_55","doi-asserted-by":"crossref","first-page":"236","DOI":"10.1109\/TASSP.1984.1164317","article-title":"Signal estimation from modified short-time fourier transform","volume":"32","author":"Griffin","year":"1984","journal-title":"IEEE Trans. Acoust. Speech Signal Process."},{"key":"ref_56","unstructured":"(2013). IEC 61672-1:2013\u2014Electroacoustics\u2014Sound Level Meters\u2014Part 1: Specifications, IEC."}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/17\/12\/2758\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T18:51:46Z","timestamp":1760208706000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/17\/12\/2758"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2017,11,29]]},"references-count":56,"journal-issue":{"issue":"12","published-online":{"date-parts":[[2017,12]]}},"alternative-id":["s17122758"],"URL":"https:\/\/doi.org\/10.3390\/s17122758","relation":{},"ISSN":["1424-8220"],"issn-type":[{"type":"electronic","value":"1424-8220"}],"subject":[],"published":{"date-parts":[[2017,11,29]]}}}