Joel Åkesson and Jonas Lindh

Voxalys AB and
Division of Speech and Language Pathology
Department of Clinical Neuroscience and Rehabilitation
Institute of Neuroscience and Physiology
Sahlgrenska Academy at University of Gothenburg

This study aims at evaluating the effects of recording material consisting of what can be called and described as ‘double filtering’. This filtering effect can here be defined as sound transmitted via GSM communication (first filter), which then passes an indeterminable distance through the air prior to being captured by another recording device, such as a mobile phone or handheld recorder’s microphone second filter). Several cases have been received recently with material either known to have been subdued to this effect or suspected to be. To date and to the authors knowledge there has been little or no focus on analyzing the reliability and effects of this type of recorded material, which is why the aim is to conduct a pilot study where the so called ‘double filtering’ effect is evaluated primarily using Automatic Voice Comparison (AVC). However, a database such as the described can in the future be used to evaluate comparisons made using phonetic and linguistic analysis.