The Headphone and Loudspeaker Test – Part I: Suggestions for controlling characteristics of playback devices in internet experiments

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 (rtt = .90 for level adjustment and rtt = .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.

Wrapped into sound: Development of the Immersive Music Experience Inventory (IMEI)

“…The subjectively adjusted sound pressure level was measured with a short section from a pop song (long term LUFS = −8.4). The test-retest reliability of HALT for detecting mono/stereo playback (r tt = 0.821) and for detecting the lower frequency limit (r tt = 0.792) is high (Wycisk et al, 2022a). As headphones of different quality were used in the HALT study, we expect a similar setting and reliability of the volume standardization in the inventory development for the IMEI.…”

“…HALT comprises three individual playback device screening tests A, B, and C (the latter developed by Woods et al, 2017). For a prevalence of 75% it would optimal to use all three tests according to the utility-driven approach described by Wycisk et al (2022b) in the following way: A Participant has to pass test C and at least one of tests A and B to be classified as a headphone user. To pass a screening test a participant needs a minimum of 6, 3, and 5 correct responses for test A, B, and C, respectively.…”

The Headphone and Loudspeaker Test–Part II: A comprehensive method for playback device screening in Internet experiments

“…With the Headphone and Loudspeaker Test (HALT) Part I and Part II, we wanted to provide a tool to counter this predicament by remote testing playback device characteristics in Internet experiments. In the previous study, HALT Part I (Wycisk et al, 2022), we suggested a procedure to standardize level adjustments, detect stereo/mono playback and assess lower frequency limits of the playback devices. Subsequently, in HALT Part II, we focused on the identification of playback device types.…”

“…As in HALT Part I (Wycisk et al, 2022), HALT Part II was meant to perform in ordinary non-optimized listening environments and with sound devices of diverse quality.…”

“…The assigned quality level in this study is only a subjective classification. As in HALT Part I (Wycisk et al, 2022), we used the browser-based survey platform SoSci Survey (www. sosci survey.…”