This　paper　proposes　a　novel　voice　activity　detection　(VAD)　algorithm　to　improve　the　speech　detection　robustness　in　noisy　environments.　In　the　proposed　algorithm,　two-stage　mel-warped　Wiener　filter　is　introduced　to　improve　the　performance　of　voice　activity　detector　based　on　spectral　entropy.　Then　an　improved　decision　rule　based　on　spectral　entropy　was　derived.　We　have　evaluated　system　performance　under　noisy　environments　using　NOISEX-92　database　and　recorded　speech　signals.　Experimental　results　indicate　that　our　approach　exhibits　considerable　improvements　in　the　degraded　environment.