Analysis of LD-CELP coder output with Sound eXchange and Praat software
Lani Rachel Mathew, Ancy S. Anselam, Sakuntala S. Pillai · 2014
This paper describes the analysis of the audio and speech output of the 16 kb/s Low Delay CELP algorithm (LD-CELP). For various speech file conversions, the SoX (Sound eXchange) tool is used. Praat software is used to extract details regarding the quality of the sound synthesized by the coder. The C program of the coder was compiled using the GCC compiler in the Linux environment and executed using the GNU Make utility. File compression ratio of 5 was achieved. The bit rate obtained is 16 kb/s, i.e. a reduction by 4 times of the original bitrate. The perceptual quality of the reconstructed audio output is very good, and this is evident from the spectrogram, pitch, intensity and formant waveforms obtained.