Similar to the below link, I operate in a fast pace retail environment. Each day I have two bills from Square, one for the payment processing costs, and a virtual one for any sales we missed because staff did not get an audible alert that a card had failed and the customer got the item for free.
I'm sure coding the Mastercard/Visa branding was fun but having different sounds for Mastercard and Visas is useful to exactly 0% of customers but having an alert for failed cards would be useful to about 100%.
May I suggest that users can choose their own failed card alert so that if we don't want to play a loud shaming klaxon (like most of your competitors) we can instead choose something that will grab our attention without making it a negative customer experience.
That would really make Square stand out in the marketplace.
https://community.squareup.com/t5/Orders-Menu-Items-Catalog/Feature-Request-Declined-Payment-Sound/m...
