If you’ve got audio devices that you wish to test, research engineer and sound designer Dr. Stéphane Pigeon’s website Audiocheck has a series of audio tests to benchmark your audio equipment. It’s also extremely useful to help you decide or narrow down the options for an audio device you would like to purchase. Just go to their website and click on a test page for the kind of device you are using. For example, you can test headphones by clicking here. That page will test your headphones for frequency response, quality, wiring (whether your headphone routes audio to the right earpiece or not), binaural test, dynamic range, spectral flatness, etc. The test is more appreciable if you use two separate headphones that are quite different, say, an entry level one and a higher end one.
As you can see, each test is explained in its particular section where the audio file to be played is embedded. Apart from the headphone test, there are various other tests, such as:
There is also a useful table on the efficacy of earplugs that are reviewed on the site. It takes into account factors such as the isolation they provide, the ease of use, comfort, and price. There are even blind audio tests that challenge you to find differences in audio frequencies, if you’re up for it.