diff --git a/MkvOpusEnc.py b/MkvOpusEnc.py
index 32d5671..c51bbed 100644
--- a/MkvOpusEnc.py
+++ b/MkvOpusEnc.py
@@ -32,7 +32,7 @@ class Tee:
 
 def check_tools():
     """Checks if all required command-line tools are in the system's PATH."""
-    required_tools = ["ffmpeg", "ffprobe", "mkvmerge", "sox", "opusenc", "mediainfo"]
+    required_tools = ["ffmpeg", "ffprobe", "mkvmerge", "sox_ng", "opusenc", "mediainfo"]
     print("--- Prerequisite Check ---")
     all_found = True
     for tool in required_tools:
@@ -78,9 +78,9 @@ def convert_audio_track(stream_index, channels, temp_dir, source_file, should_do
     ffmpeg_args.extend(["-c:a", "flac", str(temp_extracted)])
     run_cmd(ffmpeg_args)
 
-    # Step 2: Normalize the track with SoX
-    print("    - Normalizing with SoX...")
-    run_cmd(["sox", str(temp_extracted), str(temp_normalized), "-S", "--temp", str(temp_dir), "--guard", "gain", "-n"])
+    # Step 2: Normalize the track with SoX NG
+    print("    - Normalizing with SoX NG...")
+    run_cmd(["sox_ng", str(temp_extracted), str(temp_normalized), "-S", "--temp", str(temp_dir), "--guard", "gain", "-n"])
 
     # Step 3: Encode to Opus with the correct bitrate
     bitrate = "192k"  # Fallback