Tried adding a key explaining why we want to access the microphone.

bluej/package/greenfoot-build.xml

@@ -266,6 +266,7 @@
             <!-- <option value="- -add-exports=javafx.graphics/com.sun.glass.ui=ALL-UNNAMED"/> -->
             <argument value="-greenfoot=true"/>
             <argument value="-bluej.compiler.showunchecked=false"/>
+            <plistentry key="NSMicrophoneUsageDescription" value="Need microphone access for recording audio"/>
         </bundleapp>
         <!-- We have to manually copy the lib directory ourselves because appbundler
                     flattens the directory structure -->