Cluster · Sound out and in

Audio tests.

Seven instruments for sound — five that play it out and two that listen in. They tell you which channel is actually playing, whether a pair of headphones is wired the way it is labelled, how finely you can tell two pitches apart, how to shift water out of a speaker grille, what your ears do at a frequency you choose, what note is in the room, and how far a voice reaches between its lowest and highest steady note — each of them as an estimate the page can stand behind. Checking a microphone as a call device is a different job and lives in Camera & Mic.

• Utility

  Water Eject

  A 220 Hz to 110 Hz sweep for a speaker that got wet — with the cone travel each frequency asks for, printed as it descends.

• Scored test

  Perfect Pitch Test

  Name a tone with no reference, or run the staircase that finds the smallest pitch gap you can reliably hear — in cents.

• Scored test

  Headphone Test

  Six randomised trials and a verdict — correctly wired, swapped, one channel dead, or mono. It hides which side is playing, which is the only way swapped wiring shows up.

• Instrument

  Sound Test

  Left, right and both — the fastest way to find a dead channel or a swapped cable.

• Instrument

  Tone Generator

  A clean tone at a frequency you choose, for checking response and buzz.

• Instrument

  Pitch Detector

  The note in the room — name, hertz and cents against A4 = 440, with the clarity figure behind the estimate.

• Instrument

  Vocal Range Test

  Sing down and sing up: the two ends it was willing to record, the span in semitones and octaves, and the evidence for each.