###### Abstract
However, it has been reported that most electro-acoustic devices are designed through \"experience\" and \"trial-and-error\" due to the non-availability of acoustic component's impedance, precisely a black cloth (very low acoustic flow resistance) and white cloth (much higher flow resistance) that generally covers the speaker flange. In their work, [PERSON] and [PERSON] [29] measured the impedance of an acoustical speaker's impedance and highlighted that the acoustic resistance of a meshed cloth could prove to be influential in optimizing the transient response of larger speaker drivers into smaller enclosures. Both woven and non-woven materials result in acoustic impedance. Woven materials are repeatable, uniform, and have less than 10% maximum performance deviation, however, they are costly. In contrast, non-woven materials are cheap but show 30% acoustic resistance variation and are affected by humidity. Acoustic meshes can improve impulse response settling time (damping) and be modeled as a \"resistor\" across an inductor or capacitor or other tuned circuit. Acoustic meshes control venting, air bearing, damping, acoustic transparency and absorption of dirt, dust, and moisture. Acoustic cloths also provide for the chuffing of the vented pole piece resulting from air velocity turbulence and reduces the volume of air in the vicinity of the vented pole piece to reduce the vent noise and cooling requirements. In 2017, [PERSON] [30] reviewed the acoustical laboratory methods for determination of porous material's morphological characteristics. Various studies have been carried out on the ECM modeling of the microspeker. For example, [PERSON] et al. [13] have used ECM to study the performance of a flat-panel loudspeaker, generally used for portable multimedia. To improve and control the overall sound-pressure performance of cellular phones, many scholars conducted SPL research on microspeakers of the cellular phones for SPL investigations. The resistance of the ventilation cloths (papers) to the airflow changes the amount of air passing through it; hence, ventilation cloths can adjust the sound quality. The use of ventilation cloths has been widely adopted in the industry for acoustic purposes, but the knowledge required to properly choose ventilation cloths is not widely available in the literature. As aforementioned, the ventilation cloths are selected based on \"experience\" and \"trial-and-error.\" The lack of research data on and analyses of various ventilation cloths to determine resistance to the sound propagation limits the development of electroacoustic products (microspeakers, earmuff headphones, earphones, etc.). In this study, the influence of different ventilation cloths on the frequency response of the microspeaker was investigated. An inverse calculation method was used to obtain the acoustic resistance of the ventilation cloths to predict the frequency response curve with a greater accuracy. Particle swarm optimization (PSO) was employed to estimate the acoustic resistance of the ventilation cloths using initially measured frequency response as a target function. Furthermore, the acoustic impedance and frequency response of five different types of woven and five different types of non-woven acoustic ventilation cloths were studied.