# Open-Plan Offices: Comparison of Methods for Measuring Psychoacoustic Intelligibility Parameters
## 1 Introduction  
Open-plan offices have gained popularity as spaces that foster communication among users, primarily due to the favorable acoustic conditions that enhance speech intelligibility [1]. However, despite this advantage, open-plan offices often suffer from high levels of background noise caused by office equipment and multiple speakers. This background noise has been associated with user discomfort, increased stress, and reduced productivity [2]. Consequently, addressing the acoustic challenges of open-plan offices through appropriate architectural design elements becomes crucial. Building materials and furniture influence the propagation of sound waves, affecting factors such as reverberation and speech intelligibility within the office enclosure [3, 4]. It is evident that inadequate architectural acoustic design in open-plan offices can result in the clear audibility of background conversations, leading to distraction and negatively impacting workers' cognitive performance and overall well-being [5, 6]. The distraction caused by voices arises from the allocation of attention resources when individuals engage in conversation, and the clarity of speech directly correlates with the level of distraction experienced by individuals. To evaluate the acoustic conditions in open-plan office environments, the parameter of speech intelligibility becomes essential, as it directly influences the comfort and effectiveness of workspaces. The soundscape of open-plan offices, particularly when multiple speakers are present, has been identified as a significant source of distraction, interfering with task concentration, and causing annoyance for workers [7; 8]. Numerous studies have linked background noise generated by multiple talkers to cognitive performance deficits in open-plan office users, affecting attention, concentration, memory, collaboration, and task difficulty [9; 10; 11; 12; 13]. As a psychoacoustic parameter, intelligence has been widely employed to study the relationship between architectural acoustic design in open-plan offices and users' cognitive performance. It comprises physical and semantic factors. The physical factor involves objective methods that measure the propagation of sound waves and the reverberation of space, representing how speech is transmitted [14; 15; 16]. Objective methods, such as those standardized in ISO 3382-3:2012, incorporate parameters based on the signal-to-noise ratio (SNR) and the relationship between reverberation and intelligibility [1; 17]. On the other hand, subjective methods utilize standardized assessments of perceived intelligibility quality using categorized scales in specific study areas [18; 19]. While objective methods often utilize the Speech Transmission Index (_STI_) to measure irrelevant noise using _SNR_, the relationship between _STI_ and specific task performance characteristics, such as collaboration and accuracy, has not shown significant results [20; 21; 22; 23]. Additionally, the Reverberation Time (_RT_), which quantifies the decay duration of sound emitted by a source, and the Percentage of Loss of Articulation of Consonants (_%ALCons_), which predicts intelligibility by measuring the loss of information in unrecognized logatoms, are utilized as parameters in objective and subjective methods, respectively [15]. A psychoacoustic approach in multi-speaker environments, as highlighted by [PERSON] [24], has shown the potential to improve the writing performance of open-plan office users. The perceived soundscape in open-plan offices has been analyzed to evaluate its effects on cognitive performance, with physical-environmental factors, such as Activity Based Work (ABW) designs, associated with self-perceived unproductivity and the well-being of workers [25]. In Mexico, the ABW design is widely adopted in various workplaces, both in public and private companies, due to its cost-effectiveness and versatility.