A tire includes a tread strip configured in such a way that, beyond a predetermined radial wear threshold, at least one pair of first and second sounding cavities is exposed. Each first and second sounding cavity is arranged respectively in a first and second circumferential groove of the tread strip. Each sounding cavity of the pair is connected to the other sounding cavity of the pair by a sounding channel formed in the tread strip. Each cavity of the pair and the associated channel: open radially to the outside of the tyre, and are configured so that they are closed by a ground surface in a substantially airtight manner as they pass through a contact patch where the tyre makes contact with the ground surface.