The holes are obviously there to allow air in to the cables, and therefore your sound system. One hole wouldn't be enough because that limits your ability to have air flow through the connector. Much like a gas can, you need to have a second hole so there is no vacuum. Clearly this company was thinking ahead by adding a third hole, should there be a blockage in one hole two holes would still be open. You wouldn't have to get up ever 5 minutes to check to see if your holes were blocked would you? That would not be convenient during those long listening sessions. Of course, I'm sure they'll recommend you check for blockages before and after each listen. Cable maintenance is every bit as important as maintenance of your other analog devices such as stylus/cartridges, tape heads, and of course you ERS paper if you happen to be using it.