In internet experiments on auditory perception, playback devices may be a confounding variable reducing internal validity. A test procedure to remotely control multiple characteristics of playback devices does not currently exist. Thus, the main goals of this study were to (a) develop and (b) 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 loudness adjustments, detect stereo/mono playback, and assess lower frequency limits. In a laboratory study (N = 40), HALT – Part I was evaluated with four different 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). A test-retest analysis showed that HALT – Part I is assumed to be a reliable (rtt = .899 for level adjustment and rtt = .792 for stereo/mono detection) and an efficient (3.5 minutes for completion) method to remotely control playback devices and listening conditions. The procedure can help improve data quality in internet experiments.
Although virtual reality, video entertainment, and computer games are highly interested in three-dimensional reproduction of sound (including front, rear, and height channels), it remains unclear whether 3D-audio formats will intensify the emotional listening experience. There is currently no valid inventory for the objective measurement of immersive listening experiences resulting from audio playback formats with decreasing degrees of immersion (from 3D, to 5.1, stereo, and mono). The development of the Immersive Audio Quality Inventory (IAQI, say “Yuacky”) is considered to close this gap. An initial item list (N = 25) was derived from studies in virtual reality and spatial audio, supplemented by researcher-developed items and items extracted from historical descriptions. Psychometric evaluation was conducted by an online study (N = 222 valid cases). Based on controlled headphone playback, participants listened to four songs/pieces, each in the three formats of mono, stereo, and binaural 3D audio. The latent construct "immersive listening experience" was determined by probabilistic test theory (Item Response Theory) and by means of Many-Facet Rasch Measurement (MFRM). As a result, the specified MFRM model showed good model fit (62.69% explained variance). The final one-dimensional inventory consists of 10 items and will be made available in English and German.
In The Headphone and Loudspeaker Test – Part I (HALT Part I) we suggested a procedure to remotely control multiple characteristics of playback devices in internet experiments. HALT – Part II is a continuation of HALT – Part I. The main goals of the present study were (a) to develop screening tests and strategies for headphones and loudspeakers, and (b) a methodological approach to combine more than two screening tests, (c) to estimate data quality and required sample sizes for the application of screening tests. Based on psychoacoustic effects, screening tests were developed with which researchers can detect headphone and loudspeaker playback. In a first laboratory study (N = 40), three screening tests were evaluated with four different playback devices (circumaural and intra-aural headphones; external and laptop loudspeakers). In a final step, the procedure was validated in an internet-based study (N = 211). To enable a user-oriented parameter-based selection of suitable screening tests and also the simple application of screening strategies an online tool was programed. HALT Part II is assumed to be a reliable procedure to plan and execute screenings to detect headphone and loudspeaker playback. Our methodological approach can be used as a generic technique for optimizing the application of any screening tests in psychological research. Both HALT Part I and II complement each other to form a comprehensive overall concept to control playback conditions in internet experiments.
2021, Tonmeistertagung, Link zum Abstract
2022, DAGA, Link zum Poster