Pioneering Sustainable Over‑Ear Headphones: Thinksound’s New OV21 Debut

The OV21, Thinksound’s newest over‑ear headphone, is the first mass‑market model to be built entirely from sustainable materials. The housings are molded from Eastman’s Trēva, a cellulose‑based bioplastic that incorporates over 40 % biobased content sourced from sustainably harvested trees.

Founded in 2009 in Burlington, Ontario, Thinksound was established by engineer Aaron Fournier, who set out to create audio gear that honors the craft of music professionals. The brand has earned repeated praise: Stereophile has named it Recommended Component for nine consecutive years, and Digital Trends has honored it with Editor’s Choice awards on multiple occasions.

Sustainability has long been a core principle at Thinksound. The company initially used post‑consumer recycled materials and regrind in its earlier models, but those limited the ability to push product boundaries. “Finding a material that delivers both ecological responsibility and uncompromised acoustics was a game‑changer,” says Fournier. “Trēva enabled us to achieve that balance.”

Trēva, a USDA‑certified biobased polymer, is engineered to deliver superior acoustic performance while also offering the durability, chemical resistance, and processability required for high‑end consumer electronics.

We evaluated a range of conventional headphone plastics, but none matched Trēva’s dual promise of low environmental impact and top‑tier sound quality. Once we saw Eastman’s data, we seized the opportunity. All prior candidates were rejected because they forced a trade‑off between sustainability and acoustic excellence, and we weren’t prepared to accept either compromise.

Fournier explains that Trēva was chosen not only for its accessibility but also because it passed Thinksound’s stringent acoustic and durability tests. “Trēva gave us the flexibility to innovate while staying true to our environmental commitments,” he says. “We can now design a wider range of audio products without compromising quality.”

The OV21 is manufactured in China by a long‑time partner of Thinksound, with whom the company has collaborated for over 16 years. According to the injection‑molding plant, the transition to Trēva was seamless, with no production delays or technical challenges.

Looking ahead, Thinksound is prototyping two new wireless headphone models that will also utilize Trēva, and possibly Tritan. Tritan, a proprietary amorphous copolyester, is available in a Tritan Renew variant containing 50 % certified recycled content.