5. A method for decoding an encoded speech signal obtained by sinusoidal analytic encoding of an input speech signal, comprising the steps of: deciding whether the input speech signal is voiced or unvoiced; and adding a noise component to a sinusoidal synthesis waveform based on pitch intensity information as a parameter of pitch intensity detected in all bands of a voiced speech portion of the input speech signal on the basis of results of the step of deciding whether the input speech signal is voiced or unvoiced.
7. The speech decoding method as claimed in claim 5, wherein a bandwidth of the noise component added to the sinusoidal synthesis waveform is controlled in response to the pitch intensity information.