Professional paper
https://doi.org/10.36978/cte.10.1.3
Investigation of Acoustic Quantities in a School Environment Using a Smartphone and the Phyphox Application
Karolina Dvojković
orcid.org/0000-0002-2494-2778
; Vukovar High School
*
Jasenka Celić
; Matija Antun Reljković Gymnasium Vinkovci
* Corresponding author.
Abstract
Smartphones with built-in sensors are increasingly used as auxiliary measuring devices in science education. This paper presents a didactic application of a smartphone and the Phyphox application for investigating acoustic quantities in a school environment. Two experiments were carried out: the determination of the speed of sound in air using the reflection method with the Sonar tool, and the analysis of the relative decrease in uncalibrated sound pressure level as a function of distance from the sound source.
The measurements were performed using an iPhone 14 Pro running iOS 26.2, and the data were processed in MS Excel. At an air temperature of t=(31.6±1.0) ℃, the speed of sound obtained from linear regression was 350.9 m/s, which agrees well with the theoretical value of (349.6±0.6) m/s. In the second experiment, a Dyson Cyclone V10 vacuum cleaner operating at its lowest power setting was used as the sound source. Since the Phyphox readings were not compared with a calibrated sound level meter, they were used only for relative analysis. In the indoor setting, a classroom measuring approximately 5.0 m × 4.6 m × 2.7 m, a slope of approximately 8.6 dB per decade was obtained, whereas outdoors the slope was 22.2 dB per decade. The results show that room conditions, reflections, microphone orientation, and the lack of device calibration significantly affect the measurements.
Keywords
Phyphox; speed of sound; sound pressure level; smartphone; physics teaching
Hrčak ID:
348327
URI
Publication date:
26.6.2026.
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