ne of the most difficult times to employ staff to answer statements, inventory status etc. the calls. The fax information sent is chosen during a normal telephone call to the voice processing system. During this call their fax machine 37.1.3 Voice response number is entered by the caller. When the desired information has been selected, the system automatically dials up the identified fax Voice response systems are used to allow callers access to databases machine and sends the information. using a telephone. These systems require the callers to specify the The problem with this approach is that the owner of the system data they are looking for, and SO intrinsically are interactive services pays for the call. It is not surprising therefore that many of the 37/4 Voice processing applications of this technology involve closed user groups (such as potentially allow different manufacturers' systems to inter-work and bank account holders), which allows a charge to be readily levied users to be able to use just one set of command structures. for this service. However, the transmission of messages between voice mail sys- However, according to industry sources approximately 80% of the tems by these techniques is at best only moderately faster than real installed base of fax machines support the reverse polling mode of time. For this reason geographically distributed voice mail systems operation. Here the fax response system would simulate a fax are generally used only where necessary, such as in the transatlantic machine already loaded with a document. The caller could then situation. The great majority of voice mail systems at present are not make his fax dial up the system and it would send him the document. distributed, but work by having users connect to them using private This feature is not widely used at present. or public telephone facilities. In the US the majority of sales are for systems of 4 lines upwards. 37.1.5 Voice Mail There are many features in the currently available voice mail systems. They use DTMF to