diff --git a/sndinfo.txt b/sndinfo.txt
index 41b9ea1..7fdcf02 100644
--- a/sndinfo.txt
+++ b/sndinfo.txt
@@ -1,2 +1,3 @@
 kiri/gretchencounter_click "sounds/kirigretchencounter_click.ogg"
 kiri/gretchencounter_blip  "sounds/kirigretchencounter_blip.ogg"
+kiri/gretchencounter_onoff "sounds/kirigretchencounter_onoff.ogg"
diff --git a/sounds/kirigretchencounter_onoff.ogg b/sounds/kirigretchencounter_onoff.ogg
new file mode 100644
index 0000000..04d7ad4
Binary files /dev/null and b/sounds/kirigretchencounter_onoff.ogg differ
diff --git a/source_data/Makefile b/source_data/Makefile
index 46356ff..dec6948 100644
--- a/source_data/Makefile
+++ b/source_data/Makefile
@@ -7,6 +7,7 @@ all : \
 	../sprites/bright_kgcmb0.png \
 	../sounds/kirigretchencounter_click.ogg \
 	../sounds/kirigretchencounter_blip.ogg \
+	../sounds/kirigretchencounter_onoff.ogg \
 	../sprites/kgcpa0.png \
 	../sprites/kgcpb0.png \
 	../sprites/bright_kgcpa0.png \
@@ -85,3 +86,6 @@ all : \
 
 ../sounds/kirigretchencounter_blip.ogg : kirigretchencounter_blip.wav
 	ffmpeg -i $^ "-filter:a" "volume=1.0" $@
+
+../sounds/kirigretchencounter_onoff.ogg : on_off_switch.wav
+	ffmpeg -i $^ "-filter:a" "volume=1.0" $@
diff --git a/source_data/on_off_switch.aup3 b/source_data/on_off_switch.aup3
new file mode 100644
index 0000000..8005d4b
Binary files /dev/null and b/source_data/on_off_switch.aup3 differ
diff --git a/source_data/on_off_switch.wav b/source_data/on_off_switch.wav
new file mode 100644
index 0000000..9d2a8d0
Binary files /dev/null and b/source_data/on_off_switch.wav differ
diff --git a/zscript.zs b/zscript.zs
index ee91735..42ece36 100644
--- a/zscript.zs
+++ b/zscript.zs
@@ -86,8 +86,7 @@ class GretchenCounter : HDWeapon
 
         KGCM # 1 {
             invoker.onSwitch = !invoker.onSwitch;
-            console.printf("onswitch: %d", int(invoker.onSwitch));
-            // TODO: Play sound.
+            A_PlaySound("kiri/gretchencounter_onoff");
             updateOverlay();
         }
 
@@ -150,8 +149,7 @@ class GretchenCounter : HDWeapon
             // Scale distance.
             dist *= distance_scale;
 
-
-            // console.printf("%s", type_name);
+            // Apply inverse-square falloff.
             totalReading += 1.0 / (dist * dist);
         }
 
@@ -172,8 +170,6 @@ class GretchenCounter : HDWeapon
             referenceActor = self;
         }
 
-        console.printf("kjsdcsjkdcnsdjkcnsdkjcnsdc, %d", int(onSwitch));
-
         // ThinkerIterator iter = ThinkerIterator.Create("BFGNecroShard");
         // Actor mo;
         // int shardCount = 0;