RoomPhonic – Incorporating Soundscape Techniques in the Assessment of Room Acoustics
By Md Robiul Hossain, The Galway Sound Lab, Ireland
Noise, along with poor room acoustics, can lead to dissatisfaction within the office environment and can significantly adversely affect workers’ performance. Studies have shown that background noise can lead to as much as a 66 percent drop in productivity, and as such, the need to consider the prevailing acoustic environment is now a common business need. For example, the WELL Building Standard includes ‘Sound’ as a concept and aims to bolster occupant health and well-being through the identification and mitigation of acoustical comfort parameters, while the LEED green building rating system has an indoor environment quality category that focuses on several factors, including acoustic performance.
While the current standard of reverberation time and background noise assessments yield important information regarding the overall acoustic characteristics of an (empty) room, they do not give any representation of the overall sound quality in a space – the annoyance associated with noise/sound in the workplace has many factors that are not accounted for in such assessment. A more human-centered approach to workplace acoustic comfort assessment is required and this project has been designed to achieve this by incorporating sound-quality based soundscape techniques in the assessment process. The “RoomPhonic” project has been designed to achieve just this.
RoomPhonic integrates human sound perception with psychoacoustical metrics in indoor settings. Traditional building acoustics research has focused primarily on controlling sound generated by building structures and services. To fully encompass occupants’ acoustic experiences in such buildings, the analysis of human-environment interactions has introduced the concept of the indoor soundscape. Psychoacoustical sound quality metrics have been developed to understand the impact of sound on human perception. Commonly recognized metrics for psychoacoustic evaluation include loudness, sharpness, tonality, fluctuation strength, and roughness, among others. By integrating indoor soundscape and psychoacoustic metrics, the project aims to investigate response variables specific to indoor environments and develop an objective method to gauge sound perception while respecting privacy concerns.
Occupants of indoor spaces often struggle to understand engineering terms such as sound pressure levels and decibels. Incorporating appropriate response variables can enhance their understanding of sound perception and promote overall well-being. This project underscores the importance of using response variables effectively across different indoor settings.
The project proposes a unique method to use ultra-short samples to objectively obtain psychoacoustical sound quality metrics and assess perceived annoyance. Using ultra-short samples in calculating sound quality metrics presents challenges and opportunities in room acoustics research. Traditional methods rely on longer durations to accurately capture variations in sound over time. However, advancements in signal processing and psychoacoustic modeling allow for the analysis of sound quality using very brief snippets of audio. This approach is particularly useful in indoor scenarios where privacy is a significant concern.
By carefully selecting and processing these ultra-short samples, we can extract key psychoacoustic metrics such as loudness, sharpness, tonality, and others. These metrics provide insights into how sound is perceived by humans in short bursts, enabling efficient evaluation and comparison across different sound events or environments. Using the obtained psychoacoustical sound quality metrics, the project will explore perceived annoyance among occupants through indoor soundscape assessments. Moreover, the use of ultra-short samples can contribute to the development of algorithms that simulate human auditory perception more accurately, leading to advancements in sound engineering and indoor noise management.
Figure: The RoomPhonic Project incorporates assessments using soundscapes and psychoacoustic indicators to assess the indoor environment.