A smartphone-based, privacy-aware recording system for the assessment of everyday listening situations

Resumé

When trying to quantify hearing difficulties in every-day listening situations, mostly questionnaires are used to collect and evaluate subjective impressions. Obtaining objective data outside a laboratory is relatively difficult, given the required equipment and its proper handling as well as privacy concerns emerging from long-term audio recordings in a non-regulated and populated environment. Therefore, a smartphone-based system was developed that allows long-term ecological momentary assessment. Microphones are placed close to the ears to obtain signal characteristics, e.g., interaural level differences, similar to those perceived by a listener. Currently, root-meansquare, averaged spectra and the zero crossing rate are calculated. Additional features can be implemented and the flexibility of the smartphone itself allows for additional functionality, e.g., subjective ratings on predefined scales. A simple user interface ensures that the system can be properly handled by nontech-savvy users. As only the extracted features but not the audio-data itself are stored, screening and approval of the recorded data by the test subject is not necessary. Furthermore, additional standard features, e.g., the spectral centroid, can be computed offline, utilizing the recorded features.