Abstract: This study,aims at increasing the security level of the speech signal using both the encryption and compression of signals. Initially, it has done an overview of some encryption and compression methods of speech signal. Then, a new signal with an isolation property for high and low frequencies of speech has made by using discrete wavelet and discrete cosine transform and the signal is used for encryption. The new signal has compressed the coefficients on high and low indices; thereby, the possibility of compression is also provided. Results showed that the level of security in encrypted and compressed signal has reasonably increased compared to the previous methods and deciphering has become more difficult.