Extension bell
An extension bell or extension ringer[1] is a device that generates a sound to indicate an incoming telephone call, but is not included in a telephone set itself.
Extension bells may be louder than ordinary telephone ringers. As such they may be used by persons with moderate hearing impairment to help them detect incoming telephone calls, especially when they are outside the telephone's room.[2]
The devices were in use by the late 19th century. An early Australian system at Mount Crosby, Queensland featured an extension bell which was connected to an engineer's telephone over a distance of a quarter mile.[3]
Further reading
- Lua error in package.lua at line 80: module 'strict' not found.
References
- ↑ Lua error in package.lua at line 80: module 'strict' not found.[dead link]
- ↑ Lua error in package.lua at line 80: module 'strict' not found.
- ↑ Lua error in package.lua at line 80: module 'strict' not found. Column 1.
External links
- Lua error in package.lua at line 80: module 'strict' not found.
This article incorporates public domain material from the General Services Administration document "Federal Standard 1037C".
<templatestyles src="Asbox/styles.css"></templatestyles>
 |
This article related to telephony is a stub. You can help Wikipedia by expanding it. |
