Lausanne’s Sonexos raises €5.4 million to tackle low-frequency noise from fans, compressors and even data centres

Lausanne-based DeepTech firm Sonexos has secured €5.4 million in equity financing to transition its solid-state noise control technology from lab prototypes to mass production. The round was led by Valquest Partners, with backing from Robert Bosch Venture Capital GmbH (Bosch Ventures) and industry investors. Valquest Partners' Fadi Noureddine now sits on Sonexos' board.

Sonexos' founder and CEO Mark Donaldson explained that engineers have traditionally had to choose between space, weight and silence in the pursuit of quiet. Sonexos' Plasmacoustics technology eliminates this trade-off, enabling noise control without compromise. The company was co-founded by Donaldson, who previously led SoundChip, a noise-cancelling audio codec startup acquired by DSP Group, now part of Synaptics.

Sonexos focuses on addressing low-frequency noise, such as that generated by fans, compressors and motors, which conventional methods struggle with. The company's patented Plasmacoustic Metalayer uses a software-controlled plasma layer to absorb sound at a surface, making it thin, lightweight and lacking moving parts. Tests show up to 20 dB reduction in ventilation systems and 16 dB in household appliances.

Sonexos' Plasmapanel and Plasmadrive technologies can be integrated into a wide range of products, from domestic appliances and HVAC systems to industrial and automotive applications. The company is developing an industrial ecosystem and partnering with STMicroelectronics for low-power electronics and Vandewiele Group's Roj for mass production in Europe.

In addition to acoustic applications, Sonexos is exploring opportunities in AI data centre cooling, potentially reducing fan noise and easing community noise concerns while maintaining cooling capacity. The company plans to offer turnkey solutions and an enterprise model where larger OEMs integrate Sonexos components and software into their products. The funding will be used for platform industrialisation, testing and compliance, expanding teams internationally, and protecting intellectual property.