The ear that won't keep quiet

‘Hearing is truly remarkable,’ says Francesco Gianoli. ‘We can hear sounds that are about a trillion-fold apart in intensity.’ The frequency range is equally striking. ‘The ear can detect sounds from around 20 Hz to 20 kHz (or 20 000 cycles per second).’ 

Gianoli studies the inner ear to understand how it works. His project ActivEAR, funded by an ERC Starting Grant, brings together biology, physics and engineering to investigate the tiny sensory structures inside the cochlea and the physical principles that let them operate at the limits of sensitivity.

‘Think about it: a television screen might refresh at 60 Hz. Your eye sees 60 frames per second as continuous, as a single stream. The ear follows vibrations more than three hundred times as fast, cycle by cycle, and with a resolution of just a fifth of a per cent. It can detect anything from a whisper to a clap of thunder, and it does all of this at once, operating at body temperature. No engineered device can do the same.’

So how does biology manage it? One possible answer comes from physics. ‘The ear behaves like a system close to what is called criticality’, Gianoli explains. ‘This is a unique operating point: a tipping point between stable and unstable, at the edge of which the system becomes particularly sensitive to stimuli. We have a very elegant mathematical description of it.’

‘Mathematically, one parameter has to be tuned just right.’ Biology, however, is not an engineered machine assembled from perfectly calibrated components. ‘In a living cell, one parameter depends on many others. How does a living system find that setting, and hold it?’ Gianoli asks. ‘It is a fascinating question that goes beyond hearing, because other sensory systems use this same trick.’

A biological system at its limits

The clues lie deep within the cochlea, a snail-shaped structure embedded in the temporal bone, the hardest bone in the human body.

Inside, chambers filled with fluids of different ionic concentrations create the conditions essential for hearing. It even has a battery: the endocochlear potential, which Gianoli describes as ‘the largest extracellular voltage found anywhere in the body’ and essential for the ear to function. 

The organ that encases the ear’s sensory cells is also very complex. They sit below a gelatinous membrane, among supporting cells that form delicate, beam-like triangular structures sitting on top of a vibrating ribbon of tissue. Sounds run along this ribbon as a travelling wave, transmitting mechanical energy and stimulating the sensory cells in highly specific ways. 

Until now, scientists have not been able to look inside the ear and access the cells that make hearing possible without destroying the process. ‘No one had been able to isolate a portion of the cochlea while keeping it functional,’ Gianoli explains. ‘We could not look exactly at what is going on.’

A system close to criticality

The ActivEAR project will use an experimental technique developed by Gianoli and his colleagues to study the living system while preserving its physiological conditions. The aim is to identify the biological mechanisms behind the ear’s sensitivity and understand how they exploit the underlying physical principle.

The ear does not merely receive sound. It can generate it. These faint sounds, known as otoacoustic emissions, are produced by the ear’s own sensory cells and can be measured outside the ear. Some of these are also used in hearing tests for newborns.

What intrigues Gianoli is that the theory predicts these emissions. ‘Let an amplifier drift a hair past the tipping point, and it starts oscillating on its own, the same way a microphone too close to its speaker begins to howl.’ An ear close to this edge should therefore, now and then, emit sounds on its own. Some ears do. ‘And there it is,’ he says.

When hearing fails

Gianoli’s research may also provide more clues about hearing loss. Hearing loss can make social interaction harder and contribute to isolation. It is also among the largest modifiable risk factors for dementia, although whether it is a cause remains unproven.

Gianoli suspects that a lack of sensory input plays a role. ‘We tend to think of vision as our primary sense,’ he says. ‘But Helen Keller, who was both deaf and blind, wrote that deafness was a “much worse misfortune”, because it cuts us off from the company of others. Vision connects us with things. Hearing connects us with people.’

Understanding how hearing works, and how it begins to fail, could eventually lead to better ways to prevent or treat hearing loss. For now, Gianoli’s project takes a more fundamental step: to understand how the healthy ear achieves its exceptional properties.

Coming out in academia

There is another system Gianoli wants to change: academia itself.

As a queer scientist, Gianoli had encountered few researchers open about their identity during his training in Italy, France and the United Kingdom. ‘When I moved to New York, I decided to be open with everyone from the beginning,’ he says. ‘I wanted to be a scientist who could be openly queer without apologising for it.’

For him, this is not separate from his scientific work. ‘Learning not to think constantly about career implications and simply being open is freeing,’ he says. ‘It lets you redirect a great deal of energy towards your passions and your work. There is no doubt this helps the science.’

He also sees a structural problem. Academic careers can be poorly paid and unstable, and that insecurity can weigh particularly heavily on researchers whose families, the law, healthcare, and the paperwork were never designed for. ‘We are losing many talented people because academia cannot provide the stability they desperately need,’ he says.

For Gianoli, meaningful inclusion goes beyond symbolic gestures. It means fairer hiring conditions, recognition for mentoring and advocacy work, protection of chosen names, and employment arrangements that accommodate different family structures. Yet, he says, the data needed to advance these efforts do not currently exist. 

‘There is no systematic data on LGBTQIA+ researchers in Europe and little support beyond a pat on the shoulder.’ Without proper evidence and institutional commitment, inclusion risks becoming a box-ticking exercise. ‘In some cases, you end up being used as a token: “Look, we have this too.”’

Mobility matters too. ERC funding allows grantees to move their research between institutions. For Gianoli, this flexibility can be particularly important for those who cannot take for granted that laws, public acceptance or family rights will remain unchanged in a given country.

‘We cannot rely on a steady, guaranteed path of progress in the world,’ he says. ‘Ten years ago, people believed that progress was inevitable. We have seen that this is not the case.’

A laboratory in Madrid

Gianoli believes that Madrid offers the right environment to build his new laboratory at the Universidad Autónoma de Madrid. ‘I wanted a place that would be open and accepting’, he says.

He is clear, however, about the ultimate goal: to remove the barriers that make identity matter in the first place. ‘Science has an ideal: the work should speak for itself, and who did it should not matter. For judging a result, that is right. But a colleague who mentions his wife over dinner is making small talk. Say “husband”, and the same sentence becomes a coming out.’ 

Science, he says, should be impersonal in its methods, not in its people. ‘Until that default is truly neutral, visibility is how you change it. And it costs me less than it costs a trans student. That is why I want to be visible.’

That same openness will shape the laboratory Gianoli is preparing to build. He wants students to receive solid technical training, but also to learn to communicate science clearly and accessibly while keeping it methodical, rigorous and fun.

He is excited about the challenge, but under no illusions that building a new laboratory will be easy. ‘I am excited and terrified by the task at the same time,’ he says. ‘So far, people have been very supportive and welcoming. We shall see!’

For Gianoli, the next five years will be spent exploring one of biology’s most intricate instruments. The cochlea must detect signals that differ enormously in intensity, distinguish a vast range of frequencies, and remain extraordinarily sensitive without losing control. 

And somehow, in doing so, it can produce a sound of its own. 

That tiny sound may hold a clue to the larger mystery: how biology brings a system to the edge of sensitivity, tunes it there, and keeps it working. The ear, in other words, may be whispering to us the secret to its own remarkable performance. 

Biography

Francesco Gianoli is a biophysicist who studies how the ear detects and amplifies sound. He came to the field through the violin. Trained as a physicist, he apprenticed with the master luthier Gianfranco Dindo, co-founded a violin-making school, and wrote his bachelor's thesis at the University of Turin on the acoustics of violin bridges. The bridge has a counterpart in the ear, the stapes, the tiny bone that carries vibrations from the eardrum to the inner ear. That parallel drew him to the physics of hearing.

He went on to graduate studies in physics in Trieste, Turin and Paris, and earned a PhD in bioengineering with Andriy S. Kozlov at Imperial College London. He then did postdoctoral research in A. J. Hudspeth's laboratory at The Rockefeller University. In 2026 he opened his own laboratory at the Universidad Autónoma de Madrid, supported by an ERC Starting Grant. Outside the lab, Gianoli advocates for LGBTQ+ and early-career researchers. He also translates the science of hearing into music, most notably on the album Oceans on Azimuth with the sound artist Lola de La Mata and with pianist and conductor Lana Norris.