diff --git a/docs/jspsych-audio-sequence-button-response.md b/docs/jspsych-audio-sequence-button-response.md
index 7690171..056623f 100644
--- a/docs/jspsych-audio-sequence-button-response.md
+++ b/docs/jspsych-audio-sequence-button-response.md
@@ -10,6 +10,8 @@ The trial can end when the subject responds, when the audio file has finished pl
 
 Note that the buttons are disabled during playing so the subject cannot press any button during that time.
 
+Make sure to define a CSS style for `.jspsych-audio-sequence-button-response button.highlighted` to see the button light up, and you may have to use `!important` for it to show up.
+
 ## Parameters
 
 Parameters with a default value of *undefined* must be specified. Other parameters can be left unspecified if the default value is acceptable.
@@ -72,6 +74,18 @@ The animation of the visual feedback can make use of [Semantic UI's transitions]
 
 #### Three alternative forced choice (3AFC)
 
+CSS:
+```css
+.jspsych-audio-sequence-button-response button {
+	min-width: 5em;
+	min-height: 4em;
+}
+.jspsych-audio-sequence-button-response button.highlighted {
+	background-color: #ffff00 !important;
+}
+```
+
+Javascript:
 ```javascript
 var trial = {
 	type: 'audio-button-response',
diff --git a/plugins/jspsych-audio-sequence-button-response.js b/plugins/jspsych-audio-sequence-button-response.js
index 15b5b40..250664d 100644
--- a/plugins/jspsych-audio-sequence-button-response.js
+++ b/plugins/jspsych-audio-sequence-button-response.js
@@ -1,10 +1,12 @@
 /**
- * jspsych-audio-sequence-button-response
- * Etienne Gaudrain <etienne.gaudrain@cnrs.fr>
+ * jspsych-audio-sequence-button-response for jsPsych v6.3
+ * Etienne Gaudrain <etienne.gaudrain@cnrs.fr> 2021-10-15
  *
  * Plugin for playing a sequence of audio files and getting an HTML button response
  *
  * Based on jspsych-audio-button-response.
+ *
+ * 2022-03-19: Fixed bug that ISI was applied also to last item.
  **/
 
 jsPsych.plugins["audio-sequence-button-response"] = (function() {
@@ -103,11 +105,7 @@ jsPsych.plugins["audio-sequence-button-response"] = (function() {
     plugin.trial = function(display_element, trial) {
 
         var context = jsPsych.pluginAPI.audioContext();
-        if(context !== null) {
-            var source;
-        } else {
-            var audio;
-        }
+        var audio;
 
         if(trial.visual_feedback===true && trial.i_correct===null)
             throw "'i_correct' has to be defined if visual feedback is requested.";
@@ -125,12 +123,6 @@ jsPsych.plugins["audio-sequence-button-response"] = (function() {
                 play_next_audio.i = 0;
             }
 
-            /*
-            // We un-highlight the previous button
-            if(play_next_audio.i>0)
-                $(display_element).find('#jspsych-audio-sequence-button-response-' + (play_next_audio.i-1) +' button').toggleClass('highlighted');
-            */
-
             // Is it the last stimulus, do we need to end trial?
             if(play_next_audio.i >= trial.stimuli.length) {
                 $(display_element).find(".jspsych-audio-sequence-button-response button").removeClass("disabled").prop('disabled', false);
@@ -141,34 +133,37 @@ jsPsych.plugins["audio-sequence-button-response"] = (function() {
             }
 
             // Prepare the next sound to play
-            if(context !== null) {
-                source = context.createBufferSource();
-                source.buffer = jsPsych.pluginAPI.getAudioBuffer(trial.stimuli[play_next_audio.i]);
-                source.connect(context.destination);
-                source.onended = function(){
+            jsPsych.pluginAPI.getAudioBuffer(trial.stimuli[play_next_audio.i]).then(function(buffer){
+                if(context !== null) {
+                    audio = context.createBufferSource();
+                    audio.buffer = buffer;
+                    audio.connect(context.destination);
+                } else {
+                    audio = buffer;
+                    audio.currentTime = 0;
+                }
+                audio.addEventListener('ended', function _audio_ended(){
                     $(display_element).find('.jspsych-audio-sequence-button-response button.highlighted').removeClass('highlighted');
-                    setTimeout(play_next_audio, trial.isi);
-                };
-            } else {
-                audio = jsPsych.pluginAPI.getAudioBuffer(trial.stimuli[play_next_audio.i]);
-                audio.currentTime = 0;
-                audio.addEventListener('ended', function(){
-                    $(display_element).find('.jspsych-audio-sequence-button-response button.highlighted').removeClass('highlighted');
-                    setTimeout(play_next_audio, trial.isi);
+                    if(play_next_audio.i<trial.stimuli.length){
+                        setTimeout(play_next_audio, trial.isi);
+                    } else {
+                        setTimeout(play_next_audio, 0);
+                    }
+                    audio.removeEventListener('ended', _audio_ended);
                 });
-            }
 
-            // Highlight the current button
-            $(display_element).find('#jspsych-audio-sequence-button-response-' + play_next_audio.i +' button').addClass('highlighted');
+                // Highlight the current button
+                $(display_element).find('#jspsych-audio-sequence-button-response-' + play_next_audio.i +' button').addClass('highlighted');
 
-            if(context !== null) {
-                startTime = context.currentTime;
-                source.start(startTime);
-            } else {
-                audio.play();
-            }
+                if(context !== null) {
+                    startTime = context.currentTime;
+                    audio.start(startTime);
+                } else {
+                    audio.play();
+                }
 
-            play_next_audio.i++;
+                play_next_audio.i++;
+            });
         }
 
         //display buttons
@@ -288,12 +283,11 @@ jsPsych.plugins["audio-sequence-button-response"] = (function() {
             // stop the audio file if it is playing
             // remove end event listeners if they exist
             if(context !== null) {
-                source.stop();
-                source.onended = function() {}
+                audio.stop();
             } else {
                 audio.pause();
-                audio.removeEventListener('ended', end_trial);
             }
+            audio.removeEventListener('ended', end_trial);
 
             // kill any remaining setTimeout handlers
             jsPsych.pluginAPI.clearAllTimeouts();
diff --git a/tests/res/eg-syllables-bi01.wav b/tests/res/eg-syllables-bi01.wav
new file mode 100644
index 0000000..173cf30
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diff --git a/tests/res/eg-syllables-bu01.wav b/tests/res/eg-syllables-bu01.wav
new file mode 100644
index 0000000..4037b86
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diff --git a/tests/res/eg-syllables-di01.wav b/tests/res/eg-syllables-di01.wav
new file mode 100644
index 0000000..fa56ddd
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diff --git a/tests/res/eg-syllables-du01.wav b/tests/res/eg-syllables-du01.wav
new file mode 100644
index 0000000..0a3fe14
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diff --git a/tests/test_jspsych-audio-sequence-button-response.html b/tests/test_jspsych-audio-sequence-button-response.html
new file mode 100644
index 0000000..bb8dd3f
--- /dev/null
+++ b/tests/test_jspsych-audio-sequence-button-response.html
@@ -0,0 +1,64 @@
+<!DOCTYPE html>
+<html>
+
+<head>
+    <title>Test for jspsych-html-keyboard-response-clickable</title>
+    <script src="https://cdn.jsdelivr.net/gh/jquery/jquery/dist/jquery.min.js"></script>
+    <script src="https://cdn.jsdelivr.net/gh/jspsych/jsPsych@6.3.1/jspsych.js"></script>
+    <script src="https://cdn.jsdelivr.net/gh/jspsych/jsPsych@6.3.1/plugins/jspsych-html-button-response.js"></script>
+    <link href="https://cdn.jsdelivr.net/gh/jspsych/jsPsych@6.3.1/css/jspsych.css" rel="stylesheet" type="text/css">
+    <script src="../plugins/jspsych-audio-sequence-button-response.js"></script>
+    <style>
+        .jspsych-audio-sequence-button-response button {
+            min-width: 5em;
+            min-height: 4em;
+        }
+        .jspsych-audio-sequence-button-response button.highlighted {
+            background-color: #ffff00 !important;
+        }
+    </style>
+</head>
+
+<body>
+    <script>
+    document.addEventListener('DOMContentLoaded', function(event) {
+
+        var timeline = [];
+
+        timeline.push({
+            type: 'html-button-response',
+            choices: ['start'],
+            stimulus: ""
+        });
+
+        timeline.push({
+            type: 'audio-sequence-button-response',
+            choices: ['&nbsp;', '&nbsp;', '&nbsp;'],
+            prompt: '<p>Prompt</p>',
+            stimuli: ['res/eg-syllables-bi01.wav', 'res/eg-syllables-bu01.wav', 'res/eg-syllables-di01.wav'],
+            trial_ends_after_audio: true,
+            on_finish: function(){
+                console.log("Trial is finished.");
+            }
+        });
+
+        timeline.push({
+            type: 'audio-sequence-button-response',
+            choices: ['&nbsp;', '&nbsp;', '&nbsp;'],
+            prompt: '<p>Prompt</p>',
+            stimuli: ['res/eg-syllables-bi01.wav', 'res/eg-syllables-bu01.wav', 'res/eg-syllables-di01.wav'],
+            trial_ends_after_audio: true,
+            on_finish: function(){
+                console.log("Trial is finished.");
+            }
+        });
+
+        jsPsych.init({
+            timeline: timeline
+        });
+
+    });
+    </script>
+</body>
+
+</html>