We describe an illustrative cavity model with a radially narrow acoust
ic source sphere inside the convection zone for stellar p-modes. The s
tellar transition region acts as an outer reflection boundary with par
tial leakage. Based on analytical solutions, we discuss several qualit
ative line features of stellar p-modes. This model implies that both t
raveling and standing acoustic waves could coexist in the stellar phot
osphere and chromosphere with perturbation frequency nu higher than th
e acoustic cutoff frequency nu(c). Furthermore, the source-cavity inte
rference could lead to the beating effect in stellar p-mode power peak
s in a wider frequency range.