diff --git a/nemu/src/device/audio.c b/nemu/src/device/audio.c
index 7263ae8..16cf7bf 100644
--- a/nemu/src/device/audio.c
+++ b/nemu/src/device/audio.c
@@ -42,8 +42,8 @@ static void audio_callback(void *userdata, uint8_t *stream, int len) {
   int32_t out_bound_cnt = read_cnt - to_end_cnt;
   memset(stream, 0, len);
   if (out_bound_cnt > 0) {
-    // memcpy(stream, sbuf + pos_read, to_end_cnt);
-    // memcpy(stream + to_end_cnt, sbuf, out_bound_cnt);
+    memcpy(stream, sbuf + pos_read, to_end_cnt);
+    memcpy(stream + to_end_cnt, sbuf, out_bound_cnt);
   } else {
     memcpy(stream, sbuf + pos_read, read_cnt);
   }