diff --git a/openvidu-testapp/src/app/components/video/video.component.ts b/openvidu-testapp/src/app/components/video/video.component.ts
index 4d04828b..dce634aa 100644
--- a/openvidu-testapp/src/app/components/video/video.component.ts
+++ b/openvidu-testapp/src/app/components/video/video.component.ts
@@ -339,7 +339,7 @@ export class VideoComponent implements OnInit, OnDestroy {
 
     async speechToText() {
         if (this.captionIcon === 'closed_caption') {
-            await this.streamManager.stream.session.subscribeToSpeechToText(this.streamManager.stream);
+            await this.streamManager.stream.session.subscribeToSpeechToText(this.streamManager.stream, 'es');
         } else {
             await this.streamManager.stream.session.unsubscribeFromSpeechToText(this.streamManager.stream);
         }