### Background and Conceptual Framework
\begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Main Author** & **Year** & **Description of Innovation** & **Specification** & **Reference** \\ \hline [PERSON] et al. & 2015 & Noise analysis in military vehicles (noise pressure level increases with engine rpm) & Noise analysis in military vehicles & [83] \\ \hline [PERSON] et al. & 2016 & Use of metamaterials as a potential alternative for noise control in civilian and military vehicles & Metamaterials for acoustic comfort in civilian and military vehicles & [84] \\ \hline [PERSON] et al. & 2017 & Use of various types of fibrous materials, such as inorganic and metallic fibers, synthetic fibers, natural fibers and nanofibrous membranes, in noise reduction & Fibrous materials for noise reduction in vehicles & [85] \\ \hline [PERSON] et al. & 2017 & Use of green materials for acoustic insulation in the automotive and aeronautical industry & Green insulating materials & [86] \\ \hline [PERSON] et al. & 2019 & Forecast for hearing loss, exposure to noise and the need for hearing protection in the military environment (transport systems and equipment) & Noise exposure in military transport systems & [87] \\ \hline [PERSON] et al. & 2020 & Assessment of the noise level and potential risk to crews in military vehicles & Noise levels in military vehicles & [88] \\ \hline [PERSON] et al. & 2020 & Analysis of associations between HHL (Hearing Loss) and self-reported exposure to occupational and leisure noise, as well as the use of PPE (Personal Protective Equipment) in the military environment (military vehicles) & Associations between HHL and self-reported exposure to occupational noise & [89] \\ \hline [PERSON] et al. & 2021 & Development of design technologies to reduce noise and vibrations in vehicles & Design technologies for noise reduction & [90] \\ \hline [PERSON] et al. & 2021 & Exploring a passive noise reduction approach for UAVs (Unmanned Aerial Vehicles) using MPP (Micro-Perforated Panel)-type absorbers with sound-insulating materials & Passive noise reduction using microperforated panels from sound-insulating materials & [91] \\ \hline [PERSON] et al. & 2020 & Implementation of an IoT architecture for the real-time monitoring of noise pollution and noise pollution & IoT architecture for monitoring noise pollution & [92] \\ \hline [PERSON] et al. & 2021 & Noise reduction at the driver’s level by covering the engine with materials possessing sound-insulating (soft felt, hard felt, ethylene vinyl acetate) and sound-absorption properties (mineral cotton) in electric vehicles & Passive noise reduction from electric vehicle engines & [93] \\ \hline [PERSON] et al. & 2021 & Investigation of sound-absorption materials in aquatic environments (interpenetrating polymer networks (IPN), polymer foams, gradient polymers, including polymers with air voids, solid inclusions, nanomaterial fillers and phononic crystals) & Polymer materials with air voids and solid nanomaterial inclusions and phononic crystals for aquatic sound absorption & [94] \\ \hline Necula & 2022 & PhD thesis: Reducing sound pressure levels and its peaks using multistage (modular) noise attenuators & Multistage (modular) noise attenuators for noise reduction & [95] \\ \hline [PERSON] et al. & 2023 & Use of sound-insulating materials (composite rubber reinforced with hollow glass microspheres—HGM) with superior properties for ensuring acoustic comfort & Use of composite rubber reinforced with hollow glass microspheres for noise insulation & [96] \\ \hline [PERSON] et al. & 2024 & Optimization of CFRP (Carbon Fiber Reinforced Polymer) structures for improving acoustic comfort in vehicles & Optimization of carbon fiber-reinforced polymer structures for improved acoustic comfort in vehicles & [97] \\ \hline \hline \end{tabular}
\end{table} 
Table 1: _Cont._