Stuart Sierra has recently been working on lazytest, which among other things allows for continuous testing. A continuous process begs to be monitored, and if you're talking to me that means an auditory display.
(Auditory displays actually have a history of being used for similar software development tasks, like debugging. Maybe I'll put some citations here.)
Two displays are provided. The first plays an annoying whine at a volume proportional to the fraction of tests which are failing. The second plays a continuous chord which will grow more or less dissonant in proportion to the same.
This only works with lazytest tests. Also, I would not try this with headphones on. The interface is the same as that for lazytest.watch. At a REPL:
(use 'lazytest-listen.volume)
(start ["path/to/src"])
Stop it by hitting CTRL-C.
For the harmonic display, just use the lazytest-listen.harmony
namespace instead of lazytest-listen.volume.
In the interest of having something that works with hopefully zero configuration on the widest variety of computers, this just uses straight up MIDI. Could I have done something more interesting with a synthesis package? Sure, but this is basically a toy and I wanted people to be able to just compile it and run.
The audio will be played on Channel 0 on the first synthesizer javax.sound.midi dishes up. That should probably be the built-in java soft-synth. On Ubuntu (and maybe other linux distros), you're going to want to make sure you're using OpenJDK, as the sound setup for the sun jdk is not pulseaudio-friendly.
Stuart has eliminated the ability to stop watching in any way other than killing the process. That means there's no way to shut off any notes and close the synthesizer when you're done. Not doing that is fine if you are using the built-in Java synthesizer, because when the java process terminates, so does the synth. However, if you are hardcore and are using this with an external MIDI synth, you will probably get stuck notes.