The nine exercises

The nine exercises

Grouped by the skill they build rather than by name. Each has its own level (1-10) which rises from accurate answers, not from volume - and each level narrows the tolerance band, so "level 6" means something specific about your ear rather than about your patience.

Frequency

Find the frequency

A peak filter boosts or cuts a frequency drawn anywhere between 100 Hz and 12.8 kHz - not one of eight fixed octave centres, because fixed points get memorised as positions rather than heard as frequencies. Answered on a log scale. Tolerance is in octaves (±1.0 → ±0.35), so the slack is the same ratio at 200 Hz as at 8 kHz.

Name the range

The same idea, but you name the range - sub-bass, bass, low-mids, mids, high-mids, presence, air. The boosted frequency moves around inside the range each round, so you learn where its boundaries actually are.

Dynamics

Guess the compression

A repeating percussive burst through a compressor at one of three settings: weak, medium, strong. Makeup gain is matched per setting so loudness alone is not a tell. Higher levels bring the three settings closer together.

Guess the gain change

A level offset between −9 and +9 dB. Answered on a linear scale, because dB is already the perceptual unit. Tolerance stops narrowing at 1 dB on purpose: below roughly that, a level difference is not reliably audible at all, and a tighter band would test luck.

Space and stereo

Guess the reverb

Room, hall, plate or spring. Two types at low levels, four at high. Spring is built as a cascade of resonant allpass filters rather than a room simulation, because a Freeverb-style algorithm does not produce the metallic boing a spring tank has.

Guess the delay time

Any time between 20 and 640 ms. Answered on a log scale, with tolerance as a ratio (±35% → ±13%) - being 20 ms out at 40 ms and at 500 ms are completely different mistakes.

Guess the pan position

Equal-power panning anywhere between hard left and hard right. Reads as C, L86, R40. Linear scale, because equal-power panning already makes perceived position track the control linearly.

Guess the stereo width

Mid/side processing on two decorrelated noise sources. Four named widths.

This one always uses pink noise, even when you have your own audio selected. Imported clips are downmixed to mono when loaded, and a mono signal has no side channel to widen. A known limit, not a bug you found.

Character

Guess the distortion

Soft clip, hard clip, tape saturation or overdrive, each with its own makeup gain. Higher levels reduce the drive rather than changing the types, so the same four answers get harder to tell apart.