Alan, the reason the bladder is there and the holes are there is to balance the amount of air that goes into the chamber, if the holes are blocked you would get uneven volume from the keyboard smaller reads would be louder and less air would be needed. The lower notes which need more air would suffer from lack of air. In the Hohner Basso the bladder is glued down in a couple of sections that separates the air flow, bigger section for the lower octave, smaller section for the higher octave. These melodicas require a lot of attention to performance technique, in other words you can’t blast out notes, you have to use finest or you will damage the bladder. I have noticed that the Hammond BB seams to have a better airflow that the Suzuki or the Hohner, across the entire keyboard. I am not really sure why since I really have not paid to much attention to the mechanics of it, I have enough issues playing them lol.