Index: main/dsp.c
===================================================================
--- main/dsp.c	(revision 89291)
+++ main/dsp.c	(working copy)
@@ -1466,6 +1466,7 @@
 	if ((dsp->features & DSP_FEATURE_SILENCE_SUPPRESS) && silence) {
 		memset(&dsp->f, 0, sizeof(dsp->f));
 		dsp->f.frametype = AST_FRAME_NULL;
+		ast_frfree(af);
 		return &dsp->f;
 	}
 	if ((dsp->features & DSP_FEATURE_BUSY_DETECT) && ast_dsp_busydetect(dsp)) {
@@ -1474,6 +1475,7 @@
 		dsp->f.frametype = AST_FRAME_CONTROL;
 		dsp->f.subclass = AST_CONTROL_BUSY;
 		ast_debug(1, "Requesting Hangup because the busy tone was detected on channel %s\n", chan->name);
+		ast_frfree(af);
 		return &dsp->f;
 	}
 	if ((dsp->features & DSP_FEATURE_DTMF_DETECT)) {