diff --git a/src/main/java/uk/gov/hmcts/darts/audio/component/impl/OutboundFileProcessorImpl.java b/src/main/java/uk/gov/hmcts/darts/audio/component/impl/OutboundFileProcessorImpl.java
index cc7580ac8c..c9d69872b3 100644
--- a/src/main/java/uk/gov/hmcts/darts/audio/component/impl/OutboundFileProcessorImpl.java
+++ b/src/main/java/uk/gov/hmcts/darts/audio/component/impl/OutboundFileProcessorImpl.java
@@ -101,10 +101,13 @@ public List<AudioFileInfo> processAudioForPlaybacks(Map<MediaEntity, Path> media
         List<AudioFileInfo> concatenatedAndMergedAudioFileInfos = new ArrayList<>();
         if (isNotEmpty(audioFileInfos)) {
             // Used for logging only
-            String audioFilenames = audioFileInfos.stream().map(AudioFileInfo::getMediaFile).collect(Collectors.joining(", "));
+            String audioFilenames = null;
+            if (log.isDebugEnabled()) {
+                audioFileInfos.stream().map(AudioFileInfo::getMediaFile).collect(Collectors.joining(", "));
+            }
 
             List<ChannelAudio> concatenationsList = new ArrayList<>();
-            
+
             if (isWellFormedAudio(audioFileInfos)) {
                 log.debug("Audio files {} are well formed", audioFilenames);
                 List<ChannelAudio> concatenatedAudios = concatenateByChannelWithGaps(audioFileInfos);