Just when we thought we'd seen the most expensive headphones at CES 2017, in the form of Onkyo's €80,000 diamond-encrusted H900Ms, along comes French hi-fi specialist Focal with something considerably pricier - its $120,000 Utopia by Tournaire.

Maison Tournaire is a master jeweller run by father and son Philippe and Mathieu Tournaire. They have created a bespoke design for Focal based on the mark of the Trilogy, the symbol of the Tournaire jewellers, which represents the three stages of life: the past, present and future.

The design uses 18 carat gold mounted with six carats of diamonds, all hand crafted in Tournaire's workshops.

"Utopia by Tournaire is the fruit of a unique partnership - the perfect symbiosis of Focal, a manufacturer of high-fidelity speaker drivers and loudspeakers for more than 35 years, and Tournaire, a jeweller renowned for its symbolic and atypical jewellery,” says Sébastien Dumas, Focal brand and communication director.

A portion of the profits from the sales of the Utopia by Tournaire headphones and stand will be donated to the P’tit Louis association, dedicated to saving eight-year-old Louis Biscini who suffers from a rare degenerative disease, spinal muscular atrophy type 1.

MORE: Onkyo adds 20 carat diamonds to its H900M headphones