Application of a smartphone for introductory teaching of sound environment: Validation of the precision of the devices and examples of students' work

Abstract

In an introductory course for environmental/architectural acoustics in universities, it is often used the teaching method based on soundscape, in which students are asked to make a sound map with listening their surrounding acoustic environment. However, if objective measurement of sound pressure level or frequency spectrum can be introduced in such a course, it will interest students in environmental acoustics, and enable them to discuss the acoustic environment more profoundly. Measurement apparatuses are usually expensive and difficult to be used in such a course. Therefore, we consider to use a smartphone: using a smartphone with acoustic measurement applications, it can be possible to introduce an objective measurement in such an introductory course for beginners. In this study, first some applications for acoustic measurement are examined to confirm their accuracy as well as the effect of a simple handmade windscreen. Secondly, using suitable applications, as a possible work in the course, sound maps with measurement results by a smartphone are made and their examples are shown. Finally, some issues to introduce this method in actual courses are discussed.

Revisiting Acoustics Education Using Mobile Devices to Learn Urban Acoustic Environments: Recent Issues on Current Devices and Applications

“…The preceding subsection summarized our basic studies and trial tests conducted during 2012-2014 [11,12]. From the above results, an acoustics education with mobile devices was confirmed to be potentially effective, even though SPL and power spectra are measured.…”

“…In this paper, in order to update the acoustics education program for learning urban acoustic environments using mobile devices and supposing sound maps as output, which the authors proposed [11][12][13], first reviews of the main results of past studies were given as examples to outline and introduce the basic idea. Although the examples shown here are limited to small areas in cities, the method can be applied to larger-scale studies.…”

“…In the works mentioned above, original applications were used. However, in our previous work [11][12][13], we used commercial applications. In this case, the measurement accuracy of the applications also needs to be continuously checked: The results of the accuracy tests of our previous work may no longer be applicable to verify currently available tools even for educational purposes in a quantitative sense.…”

“…However, at least that study provides evidence of its accuracy in 2015. Example of a sound map with sound pressure levels (SPLs) and sound spectra: Honmachi area, Toyonaka City, Osaka, Japan, a mid-sized, moderately urbanized city [12].…”

“…Considering the above situations, we proposed an introductory teaching program of urban acoustic environments using a mobile device (hereafter, this term is used for both smartphones and tablets) with applications for acoustic measurements [11][12][13]. In these studies, the outcome was supposed to be a map with the following characteristics: comments on the acoustic environment at some specific points, in a certain area in a city, where a characteristic sound was heard, and its physical measurement data (e.g., sound spectra and A-weighted sound pressure levels) measured by mobile device (iOS) applications [11,12]. This is a kind of simple sound map describing urban acoustic environments.…”