Drat. I typed a reply and went back a page in my browser and lost it. Again ....
A good experiment. Are you saying that we should create a post in which the visitor can play from the page a-d, with only a, the control (the reference) being identified?
You know, hearing acuity is the best researched area of human hearing with well over half a century of accrued knowledge. May I suggest that there are a couple of precursors which should be at least considered to get the best out of the experiment namely:
- Is 1dB a realistic level variation? It equates to a decibel change (sound pressure) of about 10%. What does the historical archive tell us about such a small change in loudness to the human ear?
- The selection of music - is Take 5 actually the best choice? It has an audio spectrum concentrated in the middle and upper range and as an old analogue recording from the 60s (or 50s?) is technically limited
- Should the listener be listening on headphones or speakers? It's not a trivial point. The earliest work on audibility was undertaken on listeners listening on mono headphones not to a loudspeaker and later work has shown that the headphone experience and speaker listening yield different results.
There are of course numerous other factors.
Alan A. Shaw
Harbeth Audio UK