The Natural Sound Library

The International Collegium of Rehabilitative Audiology (ICRA), an affiliate of the International Society of Audiology, was formed in 1988 to enable the collaboration of researchers from around the world who focus on the rehabilitation of people who are hard of hearing. An ICRA working group was formed in response to the needs of researchers for well-documented and standardized stimuli to evaluate the performance of human listeners and hearing technologies in more realistic acoustical environments. The Natural Sound Library was created to meet these needs. Under the co-supervision of ICRA members (Søren Westermann and Claus Elberling), two MSc students at the department of Acoustics Technology at the Technical University of Denmark undertook recording, calibration and documenting the sound files (Bjerg & Larsen, 2006). The recordings were made using different methods and in different formats to enable their use by a wide community of researchers engaged in designing and testing hearing technologies and/or conducting auditory experiments in humans. The sounds were digitally recorded using an artificial head and both XY- and AB-stereo setups. The duration of all recordings is five minutes. A calibration tone and other reference sounds are provided to enable a true reproduction at the original level of the sounds. A total of 49 situations were recorded, but two of the recordings (“Flute, fast” and “Party, close with music”) have been excluded from the Natural Sound Library due to copyright issues. The recordings were approved by the ICRA membership in 2007 and ICRA charged members Karolina Smeds and M. Kathleen Pichora-Fuller to undertake making the Natural Sound Library available on T-Space at the University of Toronto.