Yet Another Biometric: Bioacoustic Signatures

Sound waves through the body are unique enough to be a biometric:

“Modeling allowed us to infer what structures or material features of the human body actually differentiated people,” explains Joo Yong Sim, one of the ETRI researchers who conducted the study. “For example, we could see how the structure, size, and weight of the bones, as well as the stiffness of the joints, affect the bioacoustics spectrum.”


Notably, the researchers were concerned that the accuracy of this approach could diminish with time, since the human body constantly changes its cells, matrices, and fluid content. To account for this, they acquired the acoustic data of participants at three separate intervals, each 30 days apart.

“We were very surprised that people’s bioacoustics spectral pattern maintained well over time, despite the concern that the pattern would change greatly,” says Sim. “These results suggest that the bioacoustics signature reflects more anatomical features than changes in water, body temperature, or biomolecule concentration in blood that change from day to day.”

It’s not great. A 97% accuracy is worse than fingerprints and iris scans, and while they were able to reproduce the biometric in a month it almost certainly changes as we age, gain and lose weight, and so on. Still, interesting.

Posted on August 21, 2020 at 6:03 AM12 Comments


Mr. H August 21, 2020 8:04 AM

Here, I give it away, as in for free, an idea for a patent;
create a keyboard that will “read” the fingerprints (all 10!) of the user that’s typing and mix it all up using a nice algo-hash, add the “audio/vocal” signature and send it across networks. Non-repudiation at its best, but once it’s cracked you’re completely toast because now “they” have your fingerprints and all, “they” become you. Biometric as we know it – just taken up a notch.

Hans August 21, 2020 9:10 AM

Well, this solves the question “how do I change a biometric key once it is compromised”. I just need to age. It will need some time though.

Singular Nodals August 21, 2020 9:29 AM

Actually, you can do it all using lunch time stomach rumblings. Most people log on sometime late mid morning.

Mr. H August 21, 2020 9:55 AM

@Singular Nodals,
Talk about random “signature” – you’re onto something here.
And I thought I was the innovative one here. You win @Singular Nodals.

Clive Robinson August 21, 2020 3:34 PM

@ Bruce,

It’s not great. A 97% accuracy is worse than fingerprints and iris scans

Firstly I’m not sure it is better than real world fingerprints, there has been a lot of “take it on trust” over what are quite suspect matches.

Whilst the legal fraternaty say “Don’t contest forensics as judges don’t like it” the number of forensics that have turned out to be at best very very poor science and at worst out and out false testimony.

The simple fact is at the end of the day “97%” is more than good enough as part of a multi-test system, which at the end of the day many identity systems are moving to as it increases reliability. After all a fingerprint authentication system is of no use if you’ve lost your finger in an accident. However if ear-lobe, hand-geometry, walking-gate and voice-print are all used as well the loss of a finger becomes a minor issue for the ID system not a total failure. Also it makes the stealing of biometrics more and more difficult, whilst a fake fingerprint is not difficult to conceal during use hand-geometery and walking gate are going to be rather more difficult as would hight, bredth and several other features such as length of major bones.

Ismar August 21, 2020 4:52 PM

What a waste of resources- although some must have got paid so from their perspective …

David August 22, 2020 6:33 AM

Why is it a waste, I suffer from the obsession with thumb prints. Like many older people my thumbprints are gone. They turn out to be a very fragile biometric as you age

echo August 22, 2020 9:39 AM

There does seem to be potentialmedical applications from this technology. I have no idea if this paper is related but improvements in scanners haveled to opening up more medical applications. Someone who knows more about this technology would be able to comment on whether portable “script kiddy” ultrasound equipment can spit out the decoding for locks.

There’s even laser ultrasound none contact stuff which works at 5cm and one metre. This paper goes into lots of the details and has pretty pictures too.

Security Sam August 26, 2020 10:34 AM

Bioacoustics Signature collection
Is the latest detection sensation
By picking up random rarefactions
And then analyzing their olfactions.

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Sidebar photo of Bruce Schneier by Joe MacInnis.