\begin{abstract} By solving numerically the full set of hydrodynamic equations governing the pulsation of a bubble, we show that shock waves are often absent in a stable sonoluminescing bubble. Nevertheless, for a wide range of physical parameters, a smooth compressional wave emerges and heats up the bubble, and the resulting black-body radiations have pulse heights and widths that agree with experimental data. Shock waves, being much less robust, are not essential for stable single-bubble sonoluminescence. \end{abstract} \pacs{PACS numbers: 78.60.Mq, 47.40.-x, 44.10.+i, 43.25.+y}