[Bruno Travi]

I have dismantled two claviettasto know the root problem. Still one sounds louder than the other. 5 holes of both are equal; They do not reach the other side.
What is the work of the 5 holes?

Photos:

https://drive.google.com/file/d/0B1I4WRon9blLQTJFS0UyQ0FUS0E/view?usp=docslist_api

https://drive.google.com/file/d/0B1I4WRon9blLcDdBMkVtWlNLREE/view?usp=docslist_api