9. The method for multi-pass echo residue detection of claim 5 , further comprising: checking an amplitude of the predetermined duration of the user speech input when the consistent noise in the predetermined duration of the user speech input is determined to be equal to or above the first predetermined consistent noise threshold, and equal to or below the second predetermined consistent noise threshold.
10. The method for multi-pass echo residue detection of claim 9 , wherein checking the amplitude includes comparing a maximum amplitude in the predetermined duration of the user speech input with a predetermined maximum amplitude threshold, and ending further analysis when the maximum amplitude in the predetermined duration of the user speech input is equal to or greater than the maximum amplitude threshold.