if not yet uploaded...

app.py

@@ -2,6 +2,7 @@ import streamlit as st
 
 if __name__ == "__main__":
   uploaded_file = st.file_uploader("Choose a file")
-  with open(uploaded_file, 'rb') as audio_file:
-    audio_bytes = audio_file.read()
-    st.audio(audio_bytes, format='audio/wav')
+  if uploaded_file is not None:
+    with open(uploaded_file, 'rb') as audio_file:
+      audio_bytes = audio_file.read()
+      st.audio(audio_bytes, format='audio/wav')