sentences:  Although this is no longer technically a point of contention, objectivists may be more likely to stress the importance of reducing total harmonic distortion in a system, while subjectivists may more often stress the importance on creating a more pleasing distribution of harmonic distortion.It is difficult, but very important, to match sound levels before comparing systems, as minute increases in loudness—more than 0.15 dB or 0.1 dB—have been demonstrated to cause perceived improvements in sound quality.Listening tests are subjected to many variables, and results are notoriously unreliable.