Segmental Sinusoidal Model for Speech Signal Coding. Periodic signal can be decomposed by sinusoidal componentwith Fourier series. With this characteristic, it can be modeled referring by sinusoidal form. By the sinusoidal model,signal can be quantized in order to encode the speech signal at the lower rate. The recent sinusoidal method isimplemented in speech coding. By using this method, a block of the speech signal with 20 ms to 30 ms width is codedbased on Fourier series coefficients. The new method proposed is quantization and reconstruction of speech signal bythe segmental sinusoidal model. A segment is defined as a block of the speech signal from certain peak to consecutivepeak. The length of the segment is variable, instead of the fixed block like the recent sinusoidal method. Coder consistsof the encoder and the decoder. Encoder works to code speech signal at variable rate. Then coded signal will betransmitted to receiver. On the receiver, coded signal will be reconstructed, so that the reconstruction signal has the nearquality compared with the original signal. The experimental results show that the average of segmental SNR is morethan 20 dB.