The headphone was finally bought and used in Spain. It was made in China. Out of materials from all around the world :

PVC / the main part of the imported pvc used in China is coming from usa (27%), Japan (22%) and others asian countries (23%).

POLYURETHANE / China is the first exportator but also the first importator of synthetic polyurethane (8,4% of the worldwide imported polyurethane) mainly coming from South Corea (24%), Japan (18%) and others asian countries (35%).

STEEL / China is the first exportator but also the first importator of steel (8,8% of the worldwide imported steel) mainly coming from Japan (47%) and South Corea (15%).
COPPER / China is the first importator of copper in the world (36% of the total worldwide imported copper) mainly from Chili (at 32%).

PERMANENT MAGNET / made out of rare earths, China has the total worldwide monopoly on the rare earths extraction (more than 90% of the total extraction).