They are also quite useful in the analysis of noise problems, e.g. that of film grain noise .
2.
We made an improvement in overcoming the defects in speech signal adaptive delta modulation ( abbr . adm ) , such as slope overloading and grain noise . in this method , numerical sliding average filtering was used for filtering decoding speech signal . experiments and analyses indicate that the method makes waveforms in good agreement between the decoding of adm and the original pulse coding modulation ( abbr . pcm ) signal , and considerably improves , the playback speech quality in naturalness , legibility and under standability