ABBlind is a double-blind audio testing device that can be used to test audio equipment. It is a project developed to help people compare two pieces of audio equipment to decide which one performs better by ear.
The device itself is very simple. Each of the audio devices to be compared are plugged to the ABBlind. The sound will come from the output port, that can be attached to some headphones or speakers. In test mode, the user can select which input is connected to the output, so that the user can match the volume levels for both inputs. When the button is pressed for a longer time, the device enters the “blind test” mode. In this mode, the user is presented with one of the inputs on the output, selected randomly. The device does not display which input is being played, instead just shows which trial are we in. The next time the button is pressed, the input selected will change (or not) again, and the trial counter will be incremented. The device allows three trials before revealing the inputs selected for each trial. This process is totally random, and the only guarantee is that the user will listen each input at least once.
This way, the user can compare by ear the differences between the two input devices, saving money in audio equipment whose differences is not able to perceive.