from pydub import AudioSegment
from io import BytesIO


def convert_to_ogg(f):
    bio = BytesIO()

    AudioSegment.from_file(f).export(bio, format='ogg')
    bio.seek(0)

    return bio

@@ -147,16 +147,33 @@
 at='ogg'
+, codec='libopus'
 )%0A    bi

Use libopus codec while converting to Voice