diff --git a/sound_objects/intern/add_sound_to_meshes.py b/sound_objects/intern/add_sound_to_meshes.py
index 40c4ace..8128b96 100644
--- a/sound_objects/intern/add_sound_to_meshes.py
+++ b/sound_objects/intern/add_sound_to_meshes.py
@@ -166,13 +166,13 @@ def add_speakers_to_meshes(meshes, context, sound=None,
         if sound is not None:
             speaker_obj.data.sound = sound
         
-        sync_audio(speaker_obj, sound, context, 
-                   sync_peak=sync_peak, 
-                   trigger_mode=trigger_mode,
-                   gaussian_stddev=gaussian_stddev,
-                   sound_bank=sound_bank, envelope=envelope)
-                
-        apply_gain_envelope(speaker_obj, envelope)
+            sync_audio(speaker_obj, sound, context, 
+                    sync_peak=sync_peak, 
+                    trigger_mode=trigger_mode,
+                    gaussian_stddev=gaussian_stddev,
+                    sound_bank=sound_bank, envelope=envelope)
+                    
+            apply_gain_envelope(speaker_obj, envelope)
 
         speaker_obj.data.update_tag()
 
diff --git a/sound_objects/intern/soundbank.py b/sound_objects/intern/soundbank.py
index cc58ba4..d4e3655 100644
--- a/sound_objects/intern/soundbank.py
+++ b/sound_objects/intern/soundbank.py
@@ -16,7 +16,10 @@ class SoundBank:
         return [sound for sound in bpy.data.sounds if sound.name.startswith(self.prefix)] 
 
     def random_sound(self) -> Sound:
-        return choice(self.sounds())
+        if len(self.sounds()) == 0:
+            return None
+        else:
+            return choice(self.sounds())
 
     def get_audiofile_info(self, sound, fps) -> (int, int):
         """