diff --git a/direct/src/interval/SoundInterval.py b/direct/src/interval/SoundInterval.py
index 24d03cfaab..6d623e65bc 100644
--- a/direct/src/interval/SoundInterval.py
+++ b/direct/src/interval/SoundInterval.py
@@ -54,7 +54,8 @@ class SoundInterval(Interval):
         # Update sound based on current time
         if (t >= self.getDuration()):
             # If end of sound reached or stop event received, stop sound
-            self.sound.stop()
+            if self.sound:
+                self.sound.stop()
             self.ignore(self.stopEvent)
         elif (event == IVAL_INIT):
             # IVAL_INIT event, start new sound
@@ -62,13 +63,14 @@ class SoundInterval(Interval):
             # start at the beginning
             if (t < 0.1):
                 t = 0.0
-            # Start sound
-            self.sound.setTime(t)
-            self.sound.setLoop(self.loop)
-            self.sound.setVolume(self.volume)
-            self.sound.play()
-            # Accept event to kill sound
-            self.acceptOnce(self.stopEvent,
+            if self.sound:
+                # Start sound
+                self.sound.setTime(t)
+                self.sound.setLoop(self.loop)
+                self.sound.setVolume(self.volume)
+                self.sound.play()
+                # Accept event to kill sound
+                self.acceptOnce(self.stopEvent,
                         lambda s = self: s.sound.stop())
         # Print debug information
         self.notify.debug('updateFunc() - %s: t = %f' % (self.name, t))
diff --git a/direct/src/showbase/ShowBase.py b/direct/src/showbase/ShowBase.py
index 5ca14a5203..095059912a 100644
--- a/direct/src/showbase/ShowBase.py
+++ b/direct/src/showbase/ShowBase.py
@@ -343,14 +343,6 @@ class ShowBase:
                 self.notify.warning("Could not load music file %s." % name)
             return sound
 
-    def unloadSfx(self, sfx):
-        if sfx:
-            del sfx
-
-    def unloadMusic(self, music):
-        if music:
-            del music
-
     def playSfx(self, sfx, looping = 0, interupt = 1, volume = None,
             time = 0.):
         if sfx:
@@ -371,14 +363,6 @@ class ShowBase:
                 music.setLoop(looping)
                 music.play()
 
-    def stopSfx(self, sfx):
-        if sfx:
-            sfx.stop()
-
-    def stopMusic(self, music):
-        if music:
-            music.stop()
-
     def dataloop(self, state):
         # traverse the data graph.  This reads all the control
         # inputs (from the mouse and keyboard, for instance) and also