Update README.md

README.md

@@ -3290,11 +3290,10 @@ configs:
 
 Libriheavy: a 50,000 hours ASR corpus with punctuation casing and context. Libriheavy is a labeled version of Librilight.
  
-This uploaded version replaces the default Libri-Light audio files with the highest quality available versions from librivox 
-and cuts them without re-encoding them. In most cases, this consists an upgrade of the source audio from a 
+This uploaded version replaces the default Libri-Light audio files with the highest quality available versions from librivox. In most cases, this consists an upgrade of the source audio from a 
 64kbps mp3 to a 128kbps mp3. 
 
-Audio files are kept as mp3 and not re-encoded to flac as in the original Librilight source archives to save disk space.
+Audio files are then re-encoded using the Opus 68kbps codec to retain quality and reduce size.
 
 - Homepage: https://github.com/k2-fsa/libriheavy
 - License: apache-2.0