Make a test tone at any frequency, or white, pink and brown noise — then download it as a file you can keep.
Start at a low volume. Test tones are far more piercing than music at the same level, especially through headphones.
The Tone Generator builds a sound from nothing — a pure frequency, a synthesiser waveform, or one of the three coloured noises — and hands you a file you can keep.
A sine wave is the pure form of a frequency with nothing else in it, which is why it is the standard for testing equipment and hearing. Square, sawtooth and triangle add harmonics and are the building blocks of synthesisers; they sound considerably louder and harsher than a sine at the same level, so turn things down before switching.
The three noises differ in where their energy sits. White spreads it evenly across all frequencies and sounds like a bright hiss. Pink has equal energy per octave, which our ears read as balanced — it is what speaker testing and most sleep apps use. Brown rolls off the top further still and sounds like heavy rain or distant surf.
It is the A above middle C, the standard reference pitch orchestras and tuners use. It is the default here for that reason.
Most people prefer brown or pink — they are deeper and less fatiguing than white noise, which can sound harsh over hours. Generate ten minutes and loop it if you want a longer file without a huge download.
You can get a rough sense of the top of your range — most adults stop hearing somewhere between 14 and 17 kHz — but your speakers and the room affect the result enormously. It is a curiosity, not a hearing test.
It spends all its time at full level, where a sine wave is only at its peak for an instant. At the same nominal level a square wave carries about 3 dB more energy and far more harsh high harmonics.
At a sensible level, yes — but start quiet. Pure tones and square waves at high volume are genuinely damaging and much more piercing than music at the same reading.