An audio-headset for acquisition of a bio-signal from a subject, comprising: - a first earpiece and a second earpiece; - an arch connecting the first earpiece and the second earpiece and comprising a hub ; wherein the arch, the first earpiece and the second earpiece are configured so that each earpiece covers the surface of an ear when the audio headset is worn by the subject; and - at least one posterior branch or at least one anterior branch , having a first end extending from the hub and a second free end (lb); wherein - the at least one posterior branch or the at least one anterior branch comprises at least one electrode configured for acquiring a bio-signal; - the at least one posterior branch or the at least one anterior branch comprises a concave surface, with a radius of curvature, configured to be in a collapsed state when the audio headset is not worn by the subject and an expanded state when the audio headset is worn by the subject; wherein - the first earpiece and the second earpiece comprise each at least one textile electrode , the earpieces and the arch being configured such that the textile electrodes rest against the skin disposed over the mastoid processes when the audio-headset is worn by the subject; characterized in that the ratio between the radius of curvature in the expanded state (CRe) and the radius of curvature in the collapsed state (CRc) is higher than 2,36 for the at least one posterior branch or higher than 2,10 for the at least one anterior branch; and in that - the at least one electrode of the at least one posterior branch or the at least one anterior branch comprises at least two pins , each pin having a first free end comprising a skin-contact interface and a second end connected to at least one flexure element , each pin being connected to a respective flexure element. - a first earpiece and a second earpiece; - an arch connecting the first earpiece and the second earpiece and comprising a hub ; wherein the arch, the first earpiece and the second earpiece are configured so that each earpiece covers the surface of an ear when the audio headset is worn by the subject; and - at least one posterior branch or at least one anterior branch , having a first end extending from the hub and a second free end (lb); - the at least one posterior branch or the at least one anterior branch comprises at least one electrode configured for acquiring a bio-signal; - the at least one posterior branch or the at least one anterior branch comprises a concave surface, with a radius of curvature, configured to be in a collapsed state when the audio headset is not worn by the subject and an expanded state when the audio headset is worn by the subject; - the first earpiece and the second earpiece comprise each at least one textile electrode , the earpieces and the arch being configured such that the textile electrodes rest against the skin disposed over the mastoid processes when the audio-headset is worn by the subject; characterized in that the ratio between the radius of curvature in the expanded state (CRe) and the radius of curvature in the collapsed state (CRc) is higher than 2,36 for the at least one posterior branch or higher than 2,10 for the at least one anterior branch; and in that - the at least one electrode of the at least one posterior branch or the at least one anterior branch comprises at least two pins , each pin having a first free end comprising a skin-contact interface and a second end connected to at least one flexure element , each pin being connected to a respective flexure element. <EOS>