Listening test
Can you hear the watermark?
ObraVera adds a hidden watermark to voice recordings so creators can prove a recording is theirs. It should be inaudible. This blind test asks your ears whether it is.
About 15 minutes, in any browser. Use headphones. On a phone, use Wi-Fi: the recordings come to about 20 MB.
Before you start
Five steps, about fifteen minutes.
- Use headphones in a quiet room. Play an original below and set the volume a little louder than you'd normally listen: these recordings are quiet.
- Learn the sound. Hear each voice with and without the watermark, and the watermark on its own, made far louder than it really is.
- Take the test. 24 short rounds. Each has A (the original), B (the watermarked version) and X, which is one of the two. Play them as often as you like, then say whether X is A or B.
- When you can't tell, guess. The scoring allows for guessing, so a guess is a useful answer.
- See your results, and if you'd like to help, send them to ObraVera anonymously with one click.
About you
Optional, and it helps.
Every question can be skipped. The answers help us read the results, for example whether people who work with audio hear more.
Privacy. Nothing leaves your computer unless you press Send. Your results contain your answers, the optional details above (your hearing answer only if you ticked the box), which link you followed to this page (for example "li" for a LinkedIn post), your browser type (for example "Safari on macOS") and the date. No audio is recorded, and we don't ask for your name or email address or store your IP address. When you press Send, Cloudflare Turnstile checks that a person, not a program, is sending; it runs only then. ObraVera uses results only to study whether its watermark can be heard, may publish findings in summary form, and keeps them until the study is published and for no longer than two years. After sending you'll see a receipt code: to have your results deleted, or to withdraw your consent, email that code to at any time. Without the code we can't tell which results are yours. Any email you send us, with a code or with your results, shows us your email address.
Learn the sound
Hear what you're listening for.
Labelled, and not scored. "Watermark on its own" is the difference between the two versions, amplified far above its real level so you can hear its character. In the watermarked recordings it is roughly 24 to 34 dB quieter than the voice.
ObraVera uses strength 15 by default. Strength 20 is stronger than that and comes first, to train your ear; strength 10 is weaker.
The test
Is X the original, or the watermarked version?
Play X at least once to answer. Play any of them as often as you like.
Recordings
Excerpts of the recordings below; the watermarked and "watermark on its own" versions were made by ObraVera.
Checking a clip with the ObraVera app? The watermark in each clip is a random test code, not linked to any work, because this test is only about whether it can be heard. The app will find the code, but with no credential or registered work to match it against it reports the check as failed. That's expected for these clips. Audio watermarked with the app is signed and registered, so the app can tell you whose work it is.