The Headphone and Loudspeaker Test – Part I: Suggestions for controlling characteristics of playback devices in internet experiments
Yves Wycisk, Reinhard Kopiez, Jakob Bergner, Kilian Sander, Stephan Preihs, Jürgen Peissig, Friedrich Platz
Abstract
Abstract In internet experiments on auditory perception, playback devices may be a confounding variable reducing internal validity. A procedure to remotely test multiple characteristics of playback devices does not currently exist. Thus, the main goals of this study were to (i) develop and (ii) evaluate a comprehensive, efficient, and easy-to-handle test procedure for the reliable control and identification of playback device characteristics in online experiments. Based on a counting task paradigm, the first part of the Headphone and Loudspeaker Test (HALT–Part I) was developed with which researchers can standardize sound level adjustments, detect stereo/mono playback, and assess lower frequency limits. In a laboratory study ( N = 40), HALT–Part I was evaluated with four playback devices (circumaural and intra-aural headphones; external and laptop loudspeakers). Beforehand, the acoustical properties of all playback devices had been measured (e.g., sound pressure level, frequency response, total harmonic distortion). The analysis suggested that HALT–Part I has high test–retest reliability ( r tt = .90 for level adjustment and r tt = .79 for stereo/mono detection) and is an efficient (3.5 minutes for completion) method to remotely test playback devices and listening conditions (sound level, stereo/mono playback). The procedure can help improve data quality in internet experiments.