The problem with low-frequency noise is that the only way to stop it is with a lot of mass. You need thick, heavy insulation and large, tuned cavities. For a data center trying to pack more cooling into a smaller footprint, or a home appliance maker chasing a quieter premium rating, that trade-off between silence and space is a hard physical limit. Sonexos, a Swiss deep-tech company, is betting that limit can be broken with a thin panel of ionized air.
Founded in 2022, the company is commercializing a plasma-based active noise control technology it calls Plasmapanel. The core idea is not to block sound with material, but to cancel it out electronically. By modulating a plasma field, the panel can absorb specific low-frequency sounds,the persistent hum from fans, compressors, and motors,in real time. The company announced a CHF 5 million (approximately $5.5 million) Pre-Series A round in October 2026, led by Valquest Partners with participation from Bosch Ventures, to move from engineered prototypes toward qualified industrial products [Bosch Media Service, October 2026].
The wedge into industrial design
Sonexos is not selling a consumer gadget. Its wedge is integration into the products of other manufacturers, where space and weight are critical design constraints. The target is the low-frequency spectrum below 500 Hz, which is notoriously difficult to manage passively. For a global maker of HVAC systems or domestic appliances, reducing this noise typically means adding bulky absorbers, increasing product size, or accepting a noisier specification. Sonexos claims its solid-state Plasmapanel can achieve similar noise reduction in a fraction of the space, effectively removing a traditional trade-off [Startupticker, October 2026].
The company is running paid prototype-integration programs with unnamed global manufacturers in the domestic appliance and HVAC sectors, with the most advanced programs targeting series production in early 2028 [Bosch Media Service, October 2026]. This is a classic hardware commercialization path: prove the technology in a lab, then prove it can be manufactured and integrated at scale alongside a partner’s existing supply chain.
A founder who knows the noise
The bet rests on technical credibility, which flows from founder Mark Donaldson’s track record. Donaldson has spent three decades in active noise control. He previously founded SoundChip, a company that developed noise-cancelling audio codecs for consumer headphones and was acquired by DSP Group, now part of Synaptics [Startupticker, October 2026]. That exit provides a relevant pedigree, though the jump from digital signal processing in earbuds to plasma physics in industrial equipment is significant.
The company has also bolstered its operational ranks with a key hire. In May 2025, Sonexos appointed Andrea Onetti as Chief Operating Officer. Onetti brings over 30 years of executive experience, including a tenure as Executive Vice President and General Manager of the MEMS Sub-Group at STMicroelectronics, a background in high-volume micro-electromechanical systems manufacturing [Sustainable Planet Switzerland, May 2025]. His hiring signals a focus on the industrialization phase that the new funding is meant to fuel.
| Role | Name | Key Background |
|---|---|---|
| Founder, President & CEO | Mark Donaldson | Former CEO/founder of SoundChip (acquired by DSP Group/Synaptics) [Startupticker, October 2026] |
| Co-founder | Ben Skelton | Former COO and Chief Applications Architect at SoundChip [Ben Skelton Contact Information] |
| Chief Operating Officer | Andrea Onetti | Former EVP/GM of MEMS Sub-Group at STMicroelectronics [Sustainable Planet Switzerland, May 2025] |
The path to production
The CHF 5 million round is a pre-Series A, a typical stage for deep-tech companies moving from lab to factory. The capital is earmarked for industrializing the Plasmapanel, supporting customer integration programs, and expanding the company’s patent portfolio [Startupticker, October 2026]. Investor Bosch Ventures brings more than capital; its parent company, Robert Bosch GmbH, is a major player in automotive components, home appliances, and industrial technology, providing potential pathways to future customers and manufacturing expertise.
A strategic collaboration announced in January 2026 with the Vandewiele Group, via its subsidiary Eutron, is a concrete step toward industrialization. The partnership aims to industrialize Sonexos’s Plasmapanel and Plasmadrive active noise reduction solutions [Sonexos and Vandewiele Group, January 2026]. Another partnership, with Italian engineering group SIT in July 2026, focuses on developing low-noise cooling solutions for data centers and energy storage systems [The Beacon Journal, July 2026]. These are not yet revenue-generating customer deals, but they are the essential alliances needed to turn a prototype into a shippable component.
The risks on the roadmap
For all its technical promise, Sonexos faces a gauntlet of commercialization risks inherent to any new physical technology targeting embedded industrial markets. The company’s near-term milestones are clear, but each carries significant execution weight.
- Integration complexity. Success depends on the Plasmapanel being designed into a partner’s next-generation product. This requires the technology to be reliable, manufacturable at cost, and easy to integrate. Any hiccup in performance or supply could delay a program and damage credibility in a conservative, relationship-driven industry.
- The cost equation. The value proposition hinges on saving space and weight. The technology must ultimately be cost-competitive with traditional passive absorption when total system design (size, weight, assembly) is factored in. If the premium for plasma-based control is too high, manufacturers may stick with bulkier but cheaper solutions.
- The scaling clock. The company is targeting series production in early 2028 for its most advanced programs [Bosch Media Service, October 2026]. The CHF 5 million round must fund the entire industrialization push and customer support until those first production revenues materialize. This timeline suggests another, larger funding round will be necessary before the company reaches sustainable operating cash flow.
The realistic customer and competitor set
The ideal customer profile for Sonexos is not an end-user, but a design engineer at a global manufacturer of equipment where low-frequency noise is a pain point and miniaturization is a premium. Think of the team designing a new server rack cooling fan for a hyperscaler, or the engineers working on the next generation of ultra-quiet kitchen hoods or heat pumps. These are buyers who value specifications and have the budget to solve a hard physics problem.
The competitive set is not other plasma startups, because there arguably aren’t any. The real competition is the status quo: conventional passive absorbers and silencers from established acoustic material suppliers, and alternative active noise control systems that use traditional speakers or actuators. Sonexos must convince customers that its approach offers a unique combination of compactness, effectiveness, and reliability that justifies switching from a known, if bulky, solution.
The next twelve months will be about de-risking the production timeline. Watch for announcements of design wins or pilot deployments with named manufacturing partners, which would signal that the integration programs are progressing toward the promised 2028 production start. The company’s ability to attract a strategic corporate investor like Bosch Ventures is a strong vote of confidence. Now it must prove the panels can roll off a line and into a product that someone has already paid for.
Sources
- [Bosch Media Service, October 2026] Bosch Ventures invests in Sonexos | https://www.bosch-presse.de/pressportal/de/en/news?search=1&id=252
- [Startupticker, October 2026] Sonexos raises CHF 5 Million to reduce noise with plasmacoustic technology | https://www.startupticker.ch/en/news/sonexos-raises-chf-5-million-to-reduce-noise-with-plasmacoustic-technology
- [Sustainable Planet Switzerland, May 2025] SONEXOS APPOINTS ANDREA ONETTI AS CHIEF OPERATING OFFICER | https://www.startupticker.ch/en/news/sonexos-raises-chf-5-million-to-reduce-noise-with-plasmacoustic-technology
- [Sonexos and Vandewiele Group, January 2026] Strategic Collaboration to Industrialise Plasmapanel® Noise Control Solutions | https://www.startupticker.ch/en/news/sonexos-raises-chf-5-million-to-reduce-noise-with-plasmacoustic-technology
- [The Beacon Journal, July 2026] Sonexos and SIT partner on low-noise cooling for data centres and energy storage | https://www.beaconjournal.com/press-release/story/214268/sonexos-and-sit-partner-on-low-noise-cooling-solutions-for-data-centres-and-energy-storage/
- [Ben Skelton Contact Information] Ben Skelton Email & Phone Number | Sonexos SA Director Contact Information
- [AudioXpress, October 2026] Bosch Ventures Backs Sonexos to Bring Plasma-Based Noise Control to Series Production | https://audioxpress.com/news/bosch-ventures-backs-sonexos-to-bring-plasma-based-noise-control-to-series-production