diff --git a/synth.c b/synth.c
index 991a11a..1ef8250 100644
--- a/synth.c
+++ b/synth.c
@@ -37,6 +37,7 @@ const int rateMultiplier = 34;
 const int rateOffset = 84;
 const int volumeMultiplier = 22;
 
+static int user_data = 0;
 volatile int runner_must_stop = 0;
 
 static espeak_ERROR set_frequency(struct synth_t *s, int freq, enum adjust_t adj)
@@ -125,8 +126,12 @@ static espeak_ERROR set_volume(struct synth_t * s, int vol, enum adjust_t adj)
 
 static espeak_ERROR stop_speech(void)
 {
+	espeak_ERROR rc;
+
 	stop_audio();
-	return (espeak_Cancel());
+	rc = espeak_Cancel();
+	user_data = (user_data + 1) % 100;
+	return rc;
 }
 
 static espeak_ERROR speak_text(struct synth_t * s)
@@ -135,7 +140,7 @@ static espeak_ERROR speak_text(struct synth_t * s)
 
 	allow_audio();
 	rc = espeak_Synth(s->buf, s->len + 1, 0, POS_CHARACTER, 0, 0, NULL,
-					  NULL);
+					  &user_data);
 	return rc;
 }