Differential Analysis of Acoustical Smartphone Recording Capabilities - a Contribution towards Smartphone-modulated Perception of Tinnitus

Loud noise is a common risk factor for physical and mental health in our industrialized world, which can trigger different sorts of health issues like permanent hearing loss and tinnitus. To mitigate noise-induced problems in daily life, smartphones can be used as an easy way to observe noise levels. As recording quality differs depending on smartphone models and calibration techniques, standardized methods are needed to acquire comparable results. To examine such possibilities in more detail, several acoustical experiments were performed regarding the recording capabilities of in-build smartphone microphones compared to an external microphone to figure out optimal smartphone recording conditions as this further increases measurement accuracy. Additionally, various different calibration approaches differing in effort and accuracy are evaluated. Results show that smartphones are capable of measuring sound pressure levels accurately with only small deviations of about +-3 dB(A). Moreover, smartphone microphones are heavily frequency dependent, which is why an approach was presented to normalize for these variations. Gathered calibration data was further brought in conjunction with sound perception data of tinnitus probands, to show an application in health issues. The presented methods provide a straightforward approach to measure sound levels with a smartphone and compare them to other device conditions, opening the use of smartphones in the modulation of sound perception in tinnitus and other conditions.