fix spelling errors (#5385)

data/presets/ZynAddSubFX/Companion/0074-Smooth Expanded.xiz

@@ -19,7 +19,7 @@
 <string name="author">Will Godfrey
 GPL V 2 or later</string>
 <string name="comments">Now has a slow long tail.
-Only really noticable on lower notes.</string>
+Only really noticeable on lower notes.</string>
 <par name="type" value="12" />
 </INFO>
 <INSTRUMENT_KIT>

plugins/lb302/README

@@ -15,7 +15,7 @@ BUG:
   to be caused by 'unexhausted buffers' That is, the problem manifests
   itself to a greater degree when the user "buffer size" configuration
   is increased to over 1024 frames or so.  The problem is much less
-  noticable when the buffer size is set to 64 frames.
+  noticeable when the buffer size is set to 64 frames.
 
 BUG:
   The synth does not make accomodations for sampling rates other than

src/core/Song.cpp

@@ -1437,7 +1437,7 @@ QString Song::errorSummary()
 	QString errors = m_errors.join("\n") + '\n';
 
 	errors.prepend( "\n\n" );
-	errors.prepend( tr( "The following errors occured while loading: " ) );
+	errors.prepend( tr( "The following errors occurred while loading: " ) );
 
 	return errors;
 }