hi, i am kousalya, newly joined member of this group,i am doing my project on line echo cancellation,i want some information regarding double talk detection algorithms, first thing i want to know is tht, is there any difference in line EC& acoustic EC in DTD implementation?.can i use dtd methods suggested for acoustic ec in line EC?i want improved algorithms compared to geigel , i have seen some papers on DTD based on orthognality theorm &cross correlation methods (NCC).can any one suggest which method will be better.& why?.. hope i will get a positive response from the group.. thanks in advance. kousalya.