# Mycelium-Based Thermal Insulation for Domestic Cooling Footprint Reduction: A Review
## 8 Discussion
The adverse effects of noise pollution on human health, particularly for individuals residing and working in urban settings, have garnered significant attention within the context of architectural design and environmental sustainability [88]. Ensuring acoustic comfort within buildings is of paramount importance, necessitating the mitigation of external noise intrusion and the attainment of appropriate interior reverberation times. Research confirms the pivotal role of acoustically comfortable environments in fostering enhanced productivity, well-being, and overall occupant health. Mycelium composites demonstrate exceptional acoustic absorption properties owing to their inherent porous and fibrous structure. Notably, laboratory investigations have indicated an impressive acoustic absorption rate of approximately 75% at 1000 Hz, a frequency within the audible range of the human ear (20 Hz to 20 kHz) [89]. This magnitude of absorption aligns well with the frequencies commonly associated with road traffic noise, showcasing the potential of mycelium-based materials to mitigate such noise intrusions. Mycelium, lauded for its ecological merits, presents potential as an acoustic insulation material; however, its application in this context needs to be improved by several limitations. While mycelium exhibits favorable attributes, such as its lightweight nature and porosity, which can contribute to sound absorption, its effectiveness as an acoustic insulator remains largely unexplored. The need for comprehensive experimentation and comparative studies comparing mycelium with established acoustic insulation materials creates a substantial knowledge gap in understanding its acoustic performance. To address this gap, it is imperative to conduct thorough empirical assessments encompassing acoustic frequencies and environmental conditions. In the absence of comprehensive real-world installations, simulation emerges as a viable approach to assess mycelium's acoustic insulation potential. Advanced simulation tools can replicate various sound propagation scenarios and allow for the estimation of mycelium's sound absorption coefficients, transmission loss, and overall acoustic performance. Using simulations, researchers can quantify mycelium's capacity to mitigate sound transmission and evaluate its suitability for diverse settings, such as buildings. This approach also enables the exploration of optimal mycelium formulations and material densities to enhance its acoustic insulation properties. A study highlights mycelium composites' economical and environmentally friendly nature compared to synthetic insulation materials. Notably, time to ignition (tig) is a critical parameter that characterizes the onset of flaming combustion and influences fire spread dynamics. The investigation reveals that mycelium composites cultivated on wheat grains and rice hulls exhibited comparable ignition times of 12 and 7 s, respectively, akin to those of XPS foam (9 s) but significantly shorter than particleboard (26 s). Furthermore, the decomposition of mycelium was observed to commence around 250 \({}^{\circ}\)C. The analysis of average heat release rate, a pivotal factor for predicting full-scale fire behavior, demonstrated that mycelium composites with wheat grains released marginally less heat (107 kW/m\({}^{2}\)) compared to XPS foam (114 kW/m\({}^{2}\)) and significantly lower heat than particleboard (134 kW/m\({}^{2}\)). Moreover, the peak heat release rate, a critical parameter influencing maximum temperature and flame spread rate, was notably lower for rice hull-based mycelium composites (133 kW/m\({}^{2}\)) in contrast to wheat grain-based mycelium composites (185 kW/m\({}^{2}\)), synthetic XPS foam (200 kW/m\({}^{2}\)), and particleboard (503 kW/m\({}^{2}\)). In terms of environmental impact, mycelium composites demonstrated reduced emissions during combustion.