1. A method, comprising: measuring a Euclidean distance between line spectrum pairs of adjacent frames representative of speech signals, wherein the Euclidian distance is given by ∑ i = 1 p ⁢ ( ω n , i - ω n - 1 , i ) 2 = ( 1 - c ) ⁢ ∑ i = 1 p ⁢ ( ω n - 1 , i - ω d ⁢ ⁢ c , i ) 2 , wherein ω n,i represents an i-th line spectrum pair of an n-th frame, ω dc,i represents an empirical mean value of the i-th line spectrum pair, and c represents a forgetting factor; and deleting a frame of the adjacent frames in response to determining that the Euclidean distance is one of less than and equal to a steady-state threshold given by T=(1−c)x 2 max [x 1. .. x p ]εΩ Σ i=1 p (x i −ω dc,i ) 2 where Ω is a p-dimensional line spectrum pair vector space.