Another way is to subjectively asses the quality of your DAC, with an objective test. The test uses a frequency sweep, which covers the whole frequency range of your DAC. Frequency range depends on your sample rate. For example, if the sample rate is 96 kHz, the frequency range extends up to 48 kHz (half the sample rate).
You can download such test files here: High Definition Test Tones Download
The sweep starts by playing frequencies that are in your hearing range, and then they will steadily increase. As the sweep enters ultrasonic range, the sound will fade away. Listen carefully; the rest of the file should remain perfectly silent!
If you hear anything while the file sweeps the ultra-sonic range, your DAC suffers from _severe_ aliasing. And it happens more often that one thinks! I am now wondering if aliasing could be the reason why some people prefer the higher sample rates... ;-)
I like this test, because it is very simple to perform and althoug loop-back testing such as RMAA is a fantastic tool, it will end up with figures that are sometimes difficult to interpret. With my suggested test, your ears will be the judge. If you hear something when you are not supposed to, you know that something is wrong that that something is audible! If you don't hear anything wrong, there might be some deficiencies left, but at least you know that you don't hear them.