a speech signal is decoded by a vocoder and the reconstructed speech samples are provided to a decoded frame check unit . the decoded frame check unit examines the energy of the reconstructed speech and compares the energy of the reconstructed speech to a range of acceptable energy values . if the energy is not within the range of energy values , a frame erasure is declared and the decoded frame is prevented from being to the speaker in the telephone . in the exemplary implementation , the speech is reconstructed by a vocoder which includes a postfilter which in turn includes automatic gain control . the automatic gain control element of a post filter includes a means for measuring the energy of the decoded speech data . this measured energy is used by the decoded frame check unit to decide whether to provide the decoded data to the user or to declare a frame erasure . this implementation reduces the amount of additional hardware necessary to implement the present invention .