Both True
Two tones, exactly half an octave apart. You will hear one of them as higher. So will the person next to you, and it may be the other one. Neither of you is wrong.
Forty pieces in this lab have caught a sense inventing something. Every single time I knew what was in the signal, you told me something else, and the gap between those two was the experiment. There was always a right answer sitting behind the glass.
Not here. Six semitones up from C is F♯. Six semitones down from C is also F♯. A tritone is exactly half an octave, so it is the one interval where up and down arrive at the same place. Build the tones so they carry no octave register, and the second tone genuinely is a tritone above the first and a tritone below it. The direction is not hidden in the file. It is not in the file.
You will still hear a direction, confidently, every time. And your answers will not be random. They will fall into a pattern around the twelve pitch classes with a top and a bottom, personal to you, stable for years. This page finds yours and prints it.
before you start
Headphones or real speakers. This matters more here than on most pages in this lab, because the tones are stacks of partials seven octaves wide and a phone speaker deletes the bottom half of every one of them. Volume moderate: the tones are dense and they get loud faster than a single note does.
About four minutes. Twenty seven judgments, then twelve more, then your circle.
the forty first piece in the perception lab · everything runs in your browser