Deuxièmes Journées Perception Sonore 2012

10 et 11 décembre 2012

CNRS Laboratoire de Mécanique et d'Acoustique

31, Chemin Joseph Aiguier

13009 Marseille


Auditory complexity augmented dB level for urban sound perception: preliminary results for the case of an elderly population.


Olfa FRAJ, Raja GHOZI et Mériem JAIDANE

Unité de recherche Signaux et Systèmes U2S, Dép. Technologies de l’Information et des Communications Ecole Nationale d’Ingénieurs de Tunis (ENIT), BP37 - Le Belvédère - 1002 Tunis.

(Work in progress, Internal report of U2S, October 2012).
The sense of security and situational awareness are key considerations in any evaluation of the well-being of elderly persons in urban spaces. With the overload of sound environments, these spaces present more and more challenges, especially on the auditory level Urban sound perception constitutes a constant communication link with the environment, critical to our sense of security, and may alter the underlying messages such as the alert sounds of an incoming train, ambulance or motorcycles. For the elderly, altered sound perception has serious impact on emotional, physical and social well-being. For instance, hearing loss is the third impairment of the elderly after arthritis and hyper-tension. As the progressive loss of high frequency perception changed the appreciation of distance and location of a sound source, the mobility- related security issues are very clear in elderly people. In this work we present preliminary results on a complexity-augmented dB indicator that better reflects senior’s sound intensity perception (dBs). The proposed age- sensitive indicator takes into account not only the measured dB sound level, but also the first and second-order moments of the signal entropy, once the sound has undergone a standardized age and gender filtering operations. In a 32-mixed subject population study, this indicator (dBs) displays overall superior correlation with the subjective responses, marked on a Likert scale, with respect to dB and dBA measures. The study is based on several queries which seek to assess the auditory perception of sound signal complexity content, and potentially invoked affects in a typical urban trajectory of an elderly population. Moreover, the study shows that the variability in auditory complexity perception is in general higher in the elderly population than that of young adults.
Notes:
- This work is part of the Tunisian French CMCU project titled: “Perceptions altérées des ambiances sonores urbaines: apport des textures audio: analyse et correction”, between U2S- ENIT, ERA-ENAU, CERMA, and CRESSON.
- The data collection and survey for this internal report have been done by Ms. Faten Hussein, assistant professor at the National School of Architecture and Urbanism of Tunis and who is a member of its Research Group on ‘Ambiances’.