Exploring the Feasibility of Using Smartphones for Measuring Sound-Level Difference as a Treatment Outcome

Provided that internal linearity can be proven, uncalibrated smartphones demonstrate a feasible method of measuring pre-/posttreatment sound levels in sustained vowels provided that the device microphone-to-source distance and recording parameters (i.e., time and frequency weighting and application) are the same. Conversely, for absolute sound pressure level measurement, calibration with a gold standard SLM is needed.