--- asterisk-13.19.0.orig/apps/app_amd.c	2018-01-11 11:44:54.000000000 -0500
+++ asterisk-13.19.0/apps/app_amd.c	2018-02-06 12:56:02.112771181 -0500
@@ -174,6 +174,7 @@
 	int silenceDuration = 0;
 	int iTotalTime = 0;
 	int iWordsCount = 0;
+	int ms = 0;
 	int currentState = STATE_IN_WORD;
 	int consecutiveVoiceDuration = 0;
 	char amdCause[256] = "", amdStatus[256] = "";
@@ -279,6 +280,10 @@
 
 	/* Now we go into a loop waiting for frames from the channel */
 	while ((res = ast_waitfor(chan, 2 * maxWaitTimeForFrame)) > -1) {
+		/* Figure out how long we waited */
+		if ( res > 0 ) {
+			ms = 2 * maxWaitTimeForFrame - res;
+		} 
 
 		/* If we fail to read in a frame, that means they hung up */
 		if (!(f = ast_read(chan))) {
@@ -289,15 +294,22 @@
 			break;
 		}
 
-		if (f->frametype == AST_FRAME_VOICE || f->frametype == AST_FRAME_NULL || f->frametype == AST_FRAME_CNG) {
-			/* If the total time exceeds the analysis time then give up as we are not too sure */
+		if (f->frametype == AST_FRAME_VOICE || f->frametype == AST_FRAME_CNG) {
+			/* figure out how long the frame is in ms */
 			if (f->frametype == AST_FRAME_VOICE) {
 				framelength = (ast_codec_samples_count(f) / DEFAULT_SAMPLES_PER_MS);
 			} else {
-				framelength = 2 * maxWaitTimeForFrame;
+				framelength = ms;
 			}
-
 			iTotalTime += framelength;
+
+			if ( f->frametype == AST_FRAME_VOICE ) {
+				ast_debug(1, "AMD: Channel [%s] frametype [AST_FRAME_VOICE] iTotalTime [%d] framelength [%d] totalAnalysisTime [%d]\n", ast_channel_name(chan), iTotalTime, framelength, totalAnalysisTime );
+			} else {
+				ast_debug(1, "AMD: Channel [%s] frametype [AST_FRAME_CNG] iTotalTime [%d] framelength [%d] totalAnalysisTime [%d]\n", ast_channel_name(chan), iTotalTime, framelength, totalAnalysisTime );
+			}
+
+			/* If the total time exceeds the analysis time then give up as we are not too sure */
 			if (iTotalTime >= totalAnalysisTime) {
 				ast_verb(3, "AMD: Channel [%s]. Too long...\n", ast_channel_name(chan));
 				ast_frfree(f);
@@ -308,7 +320,7 @@
 
 			/* Feed the frame of audio into the silence detector and see if we get a result */
 			if (f->frametype != AST_FRAME_VOICE)
-				dspsilence += 2 * maxWaitTimeForFrame;
+				dspsilence += framelength;
 			else {
 				dspsilence = 0;
 				ast_dsp_silence(silenceDetector, f, &dspsilence);