Hoot and holler networks provide “always on” multiuser conferences without requiring that users dial into the conference. These
networks came into being more than 40 years ago when local concentrations of small specialized businesses with common, time-critical informational interests. Junkyards for example, began to install their own phone wires, speakers (called squawk boxes), and microphones between their businesses to ask each other about parts customers needed. These networks functioned as crude, do-it-yourself, business-to-business intercom systems. Hoot and holler broadcast audio network systems have since evolved into the specialized leased-line networks used by financial and brokerage firms to trade stocks and currency futures and the accompanying time-critical information such as market updates and morning reports. Hoot and holler is used in various industries as a way to provide a one-to-many or many-to-many conferencing service for voice communications.
* [Source: Cisco Hoot & Holler Over IP]