How can i generate synthetic speech from LPC Encoded data

I want to do signal processing in matlab. The code of LPC is available in this link https://www.mathworks.com/help/dsp/examples/lpc-analysis-and-synthesis-of-speech.html. The code is working fine as it is but when I separate the analysis and synthesis part it is not recovering the speech. I am storing the output of LPC analysis i-e sigk and siglpc in mat files and then again reading the data of sigk and siglpc from mat files and giving data to LPC synthesis but speech is not recovering back.