diff --git a/telebot/apihelper.py b/telebot/apihelper.py
index 8a6ae75..93ba91a 100644
--- a/telebot/apihelper.py
+++ b/telebot/apihelper.py
@@ -541,7 +541,7 @@ def send_video_note(token, chat_id, data, duration=None, length=None, reply_to_m
 
 
 def send_audio(token, chat_id, audio, caption=None, duration=None, performer=None, title=None, reply_to_message_id=None,
-               reply_markup=None, parse_mode=None, disable_notification=None, timeout=None):
+               reply_markup=None, parse_mode=None, disable_notification=None, timeout=None, thumb=None):
     method_url = r'sendAudio'
     payload = {'chat_id': chat_id}
     files = None
@@ -567,6 +567,11 @@ def send_audio(token, chat_id, audio, caption=None, duration=None, performer=Non
         payload['disable_notification'] = disable_notification
     if timeout:
         payload['connect-timeout'] = timeout
+    if thumb:
+        if not util.is_string(thumb):
+            files['thumb'] = thumb
+        else:
+            payload['thumb'] = thumb
     return _make_request(token, method_url, params=payload, files=files, method='post')