Abstract: The invention features a headset, and systems including the headset, equipped with electrical sensors. The headset is suitable for use by a child and suitable for use in a gaming system, e.g., to train attention.

Abstract: A lock assembly has a lock barrel which slides in a housing so that a finger at the end of the barrel can release a latch. The lock barrel is prevented from sliding when the barrel is locked, by engagement of the finger with a blocking plate, but the barrel is freed when the key is inserted and turned. The finger is made so that it shortens if excessive axial force is applied while the barrel is locked. This shortening may be effected by including an easily rupturable connection between different sections of the finger. When the finger shortens, the connection ruptures and prevents the finger from getting near the latch to release it. Once the connection has ruptured, further movement of the barrel into the housing will bring the barrel into contact with the outer periphery of the blocking plate which is well supported.