In this paper, we propose a novel voice activity detection (VAD) scheme for low SNR conditions with additive white noise. The proposed approach consists of two parts. First, a grey magnitude spectral subtraction (GMSS) is applied to remove additive noise from a given noisy speech. By this doing, an estimated clean speech is obtained. Second, the enhanced speech by the GMSS is segmented and put into an energy-based VAD to determine whether it is a speech or non-speech segment. The approach presented in this paper is called the GMSS/EVAD. Simulation results indicate that the proposed GMSS/EVAD outperforms VAD in G.729 and GSM AMR for the given low SNR examples. To investigate the performance of the GMSS/EVAD for real-life background noises, the babble and volvo noises in the NOISEX-92 database are under consideration. The simulation results for the given examples indicate that the GMSS/EVAD is able to handle appropriately for the cases of the babble noise with the SNR above 10dB and the cases of the volvo noise with SNR 15dB and up.