## 1 Introduction  
Functionally graded materials (FGM) are ceramic-metal composites whose material properties continuously vary in the thickness direction [1; 2; 3]. This constant variation in the material characteristic guarantees that the stress field varies smoothly across the entire thickness range. The ceramic constituents in FGM plates are resistant to high temperatures due to their low thermal conductivity. A range of applications can be customized by gradually tweaking the characteristic. Ceramic metal FGM plates, for example, are a better choice for aeronautical applications in hot climates. Furthermore, because plate-like structures are less rigid in the transverse direction, they are more likely to vibrate, amplifying the acoustic radiation. As per the present scenario, control of noise in modern machine fabrication becomes important, for which FGM plates have played significant roles. In this paper, the sound radiation of the P-FGM plate is computed by solving the Rayleigh Integral with the elemental radiator approach. Parametric effects of plate variables (such as power-law index, modulus ratio, and damping loss factor) on the vibroacoustic response of a clamped, thin power-law index, functionally graded plate under point forcing are discussed. Researchers estimated that the sound radiation response of isotropic [4; 5; 6; 7; 8; 9; 10; 11], orthotropic [12; 13; 14; 15], composite [16; 17; 18], sandwich plates [19; 20; 21], and FGM [22; 23; 24; 25; 26; 27; 28; 29] plates using the Rayleigh integral method. The authors used the elemental radiator approach to estimate the sound power radiated by plate structures [29; 30; 31; 32; 33; 34; 35; 36; 37; 38]. The literature is scarce on sound radiation from FGM plates, but here is a brief review. Using the elemental radiator approach, [PERSON] et al. [22] analyzed the sound response of sandwich plates with FGM core along with the thickness. Using the Rayleigh Integral, they discussed the effect of core thickness on the overall sound power level. The authors [23] broadened their investigation to include the sound radiation and transmission loss of a vibrating functionally graded plate in terms of plate velocity and radiated sound power for point and uniformly distributed load cases. They investigated the sound transmission and reflection from unbounded panels of functionally graded materials. [PERSON] et al. [27] examined temperature-dependent porous functionally graded plate for vibration and sound radiation. They used first-order shear deformation theory with the temperature-dependent material properties to formulate the governing equation of porous FGM plates using [PERSON]'s principle and demonstrated that structural stiffness and rigidity played a significant role in the dynamics and acoustics response of porous FGM plates. [PERSON] et al. [28] expanded on their previous work to provide a semi-analytical solution to the sound radiation of functionally graded plates in a thermal environment. [PERSON] et al. [29] also presented analytical studies on sound radiation transmission loss from functionally graded plates using FSDT and elemental radiator approach. They calculated the sound radiation under variable excitation strategies. They considered the geometric mid-surface of the FGM plate as the physical neutral surface. [PERSON] et al. [39] used FSDT and the finite element method to investigate the vibroacoustic responses of P-FGM panels with various boundary conditions. According to the above literature review, most researchers, while studying the acoustic response of P-FGM plates, used the geometric mid-surface as the physical neutral surface [24; 28; 29; 37; 40; 41; 42]. However, this is not true for FGM material plates because the property varies in the thickness direction [1; 43; 44] leading to stretching-bending coupling and making it difficult to maintain interlaminar material continuities.