A method for discontinuous transmission, DTX, decision, comprising: obtaining sub-band signals by splitting an input signal; obtaining a characteristic information of each of the sub-band signals and a variation of the characteristic information of each of the sub-band signals; performing the DTX decision according to the obtained variation of the characteristic information of each of the sub-band signals, wherein the performing DTX decision is configured to indicate whether a Silence insertion Description, SID, frame shall be transmitted; and before obtaining the sub-band signals by splitting the input signal, obtaining, after detecting that an input signal being an acoustic signal, has changed from speech to noise, characteristic of the noise to initialize subsequent DTX decision; wherein the input signal is a wideband signal and the sub-band signals are a lower-band signal and a higher-band signal; or the input signal is an ultra-wideband signal and the sub-band signals are a lower-band signal, a higher-band signal and an ultrahigh-band signal; wherein performing DTX decision according to the variation of the characteristic information of each of the sub-band signals comprises: performing a combined decision on the variation of the characteristic information of each of the sub-band signals and taking a result of the combined decision as a DTX decision criterion; if the result is larger than a threshold, it is determined a SID frame shall be transmitted; otherwise, it is determined that it is unnecessary to transmit the SID frame. obtaining sub-band signals by splitting an input signal; obtaining a characteristic information of each of the sub-band signals and a variation of the characteristic information of each of the sub-band signals; performing the DTX decision according to the obtained variation of the characteristic information of each of the sub-band signals, wherein the performing DTX decision is configured to indicate whether a Silence insertion Description, SID, frame shall be transmitted; and before obtaining the sub-band signals by splitting the input signal, obtaining, after detecting that an input signal being an acoustic signal, has changed from speech to noise, characteristic of the noise to initialize subsequent DTX decision; wherein the input signal is a wideband signal and the sub-band signals are a lower-band signal and a higher-band signal; or the input signal is an ultra-wideband signal and the sub-band signals are a lower-band signal, a higher-band signal and an ultrahigh-band signal; wherein performing DTX decision according to the variation of the characteristic information of each of the sub-band signals comprises: performing a combined decision on the variation of the characteristic information of each of the sub-band signals and taking a result of the combined decision as a DTX decision criterion; if the result is larger than a threshold, it is determined a SID frame shall be transmitted; otherwise, it is determined that it is unnecessary to transmit the SID frame. performing a combined decision on the variation of the characteristic information of each of the sub-band signals and taking a result of the combined decision as a DTX decision criterion; if the result is larger than a threshold, it is determined a SID frame shall be transmitted; otherwise, it is determined that it is unnecessary to transmit the SID frame.