diff --git a/domain/src/main/java/org/oppia/android/domain/audio/AudioPlayerController.kt b/domain/src/main/java/org/oppia/android/domain/audio/AudioPlayerController.kt
index d9ac8e2691d..4e9827a6ff2 100644
--- a/domain/src/main/java/org/oppia/android/domain/audio/AudioPlayerController.kt
+++ b/domain/src/main/java/org/oppia/android/domain/audio/AudioPlayerController.kt
@@ -78,6 +78,7 @@ class AudioPlayerController @Inject constructor(
   private var nextUpdateJob: Job? = null
   private val audioLock = ReentrantLock()
 
+  private var isInitalized = false
   private var prepared = false
   private var observerActive = false
   private var mediaPlayerActive = false
@@ -95,6 +96,7 @@ class AudioPlayerController @Inject constructor(
    */
   fun initializeMediaPlayer(): LiveData<AsyncResult<PlayProgress>> {
     audioLock.withLock {
+      isInitalized = true
       mediaPlayerActive = true
       if (isReleased) {
         // Recreation is necessary since media player's resources have been released
@@ -125,24 +127,33 @@ class AudioPlayerController @Inject constructor(
 
   private fun setMediaPlayerListeners() {
     mediaPlayer.setOnCompletionListener {
-      completed = true
-      stopUpdatingSeekBar()
-      playProgress?.value =
-        AsyncResult.Success(PlayProgress(PlayStatus.COMPLETED, 0, duration))
+      audioLock.withLock {
+        completed = true
+        stopUpdatingSeekBar()
+        playProgress?.value =
+          AsyncResult.Success(PlayProgress(PlayStatus.COMPLETED, 0, duration))
+      }
     }
     mediaPlayer.setOnPreparedListener {
-      prepared = true
-      duration = it.duration
-      playProgress?.value =
-        AsyncResult.Success(PlayProgress(PlayStatus.PREPARED, 0, duration))
+      audioLock.withLock {
+        prepared = true
+        duration = it.duration
+        playProgress?.value =
+          AsyncResult.Success(PlayProgress(PlayStatus.PREPARED, 0, duration))
+      }
     }
     mediaPlayer.setOnErrorListener { _, what, extra ->
-      playProgress?.value =
-        AsyncResult.Failure(
-          AudioPlayerException("Audio Player put in error state with what: $what and extra: $extra")
-        )
-      releaseMediaPlayer()
-      initializeMediaPlayer()
+      audioLock.withLock {
+        playProgress?.value =
+          AsyncResult.Failure(
+            AudioPlayerException(
+              "Audio Player put in error state with what: $what " +
+                "and extra: $extra"
+            )
+          )
+        releaseMediaPlayer()
+        initializeMediaPlayer()
+      }
       // Indicates that error was handled and to not invoke completion listener.
       return@setOnErrorListener true
     }
@@ -251,11 +262,13 @@ class AudioPlayerController @Inject constructor(
    */
   fun releaseMediaPlayer() {
     audioLock.withLock {
-      check(mediaPlayerActive) { "Media player has not been previously initialized" }
+      check(isInitalized) { "Media player has not been previously initialized" }
+      if (mediaPlayerActive) {
+        mediaPlayer.release()
+      }
       mediaPlayerActive = false
       isReleased = true
       prepared = false
-      mediaPlayer.release()
       stopUpdatingSeekBar()
       playProgress = null
     }