| 摘要 |
The earphone 10 comprising an outer body portion 12 for sitting in the outer ear. The portion 12 is connected to a stalk 16 to fit in an ear canal of the user. The stalk 16 includes a stalk head 22 having at least one speaker least one speaker and passive noise-cancelling means including an adjustable ring 24 disposed around the stalk 16. A positioning arm 26, and control means 44 for control engagement of the positioning arm 26 with the ring 24. In use the positioning arm 26 is used to bear against and expand the adjustable ring 24 to fill a space between the exterior of the stalk 16 and the interior of the ear canal, thereby substantially blocking ambient noise. In a further embodiment the earphone includes a variety of sensors and may transmit an alarm if the user is incapacitated. |
