Intercom & Talkback tools

Intercom & Talkback tools.

Most of us have heard some time or other references being made to the theory of communication throughout the various stages of our education. In this occasion with would like to remind the six drivers that are required for said communication to take place: the issuer is who issues the message; the receiver is who receives the information; the channel or physical means through which the message is issued and/or disseminated; the code, as system of signals, rules, regulations and signs used for conveying the message’s content; the message, in regard to the content in question (data, order, words…) through which issuer and receiver contact each other with the aim of sharing it; and the context, which is related to all conditions that are external to the communication process itself, such as situation, environment, place and time, but also associated to the topic or background of what is being communicated.


The main purpose of this article is to deal with the channel. Nowadays, the physical medium being used for communication between issuer and receiver is clearly influenced by the technology that is within reach. In fact, society is increasingly leading citizens to interpersonal relationships and then the exchange of information is dependent on a technological device: a smartphone. Therefore, an interaction is created with the others, be it either a spoken conversation by means of a phone call; or written conversations and/or with icons or drawings thanks to smartphones and various applications being developed based on social media.


If these communication factors are taken to a production/business environment -thus establishing an inter-professional relationship- the same six factors are identified. The difference is that hardly any errors can exist in the given communication process, for there are many things at stake, and two in particular: the economic impact due to the “value of information content” being conveyed, and the security inherent to the message itself –in regard to the possibility of a risk associated to an occupational accident of workers and agents involved in the work environment taking place-, most especially when citizens, audience or spectators are present.


With regards to the professional side of matters, each of the six factors must be examined. On the one hand, learning for fostering efficient communication with an impact on issuer, receiver and message; technological assurances in the channel and in the code being used; and precise, customized adaptation with regards to the context, in view of the fact that each job has its own peculiar features, varying communication needs and mixed work environments.


Dynamics in a vast amount of jobs base their daily routines in a nearly-perfect communication process in order to satisfactorily achieve their own goals and the missions: Fire brigades, a hospital, the construction industry, airports, the police, hotels, air, land and sea transport, the army, security agencies, space travels, and then countless work environments.
Success is also necessary in the communications, audiovisual, leisure and entertainment worlds. There are many and quite different job profiles behind the shooting of a film, a mega concert, a musical a play, an award ceremony, a mapping, lights and sound show… amongst others. Decision making and dissemination of communication and operating orders have both an impact on individuals and/or groups of people, which can be classified as follows:


• Management professionals (production, security, protocol teams, content directors and editors, agencies, representatives, authorities…)
• Professionals featuring more technical profiles (lighting staff, stage managers, sound and video operators, rigging crew, video cameramen),
• The arts team (musicians, singers, presenters, actors and actresses, choreographers, dance crew…),
• And most specially, with presence and participation of an audience, spectators attending to shows, inauguration events, ceremonies and live events.


At present, all professional environments and human teams involved in each of them have one thing in common: their dependence on technology. Which means they all have a bond with the tools, devices and codification that are used to enable the various professionals involved in work to be able to properly perform their duties and/or comply with their responsibilities.


A very popular sentence says: Information is power. Undoubtedly this sentence is quite revealing but nowadays the proper operation of technology used for establishing communication in terms of emission, transmission and dissemination is at least as important as what this information is or means.


The presence of a mobile phone in our lives has both caused and enabled that each of us is twenty four hours a day connected and available with regards to everything relating to our personal lives, but also at a professional level. A mobile phone is the channel, the tool being most successful in regard to the technology being used for interpersonal communication processes. But is it valid in inter-professional work environments? Are all variables under control in terms of efficiency and security through the use of a mobile phone? Where and when can personal communications (a call, SMS, icon…) interfere with or taint professional communication?


The answers to these and to other questions lead us to ponder about the use of mobile phones as the only devices and therefore it becomes necessary finding other technological solutions in order to meet very specific requirements, get work done within budget, taking action in very short response times and solve situations under very demanding security levels.


The solution: Intercommunication or communication systems, also known as Intercommunicator / Talk Back. These are equipment and solutions for the transmission of orders and of an internal nature, that is, to be exclusively used by the human team involved in the relevant project, job and/or event.


In a first communication level within this type of equipment we find the well-known walkie talkies. Very much in mind and frequently used due to two main reasons: low financial cost –both with regards to purchase and during the communication process- and enormous ease of use, which translates into a short learning curve.


A walkie talkie is a radio device that may be used both as transmitter and as receiver (this being the reason why it is known as a ‘two way radio’. It was designed for military use and with the purpose of setting up portable communications between communication stations and the various units within the armed forced deployed on other places.


All walkie talkies are based on what is known as PPT (Push To Talk), a method to begin talking in half-duplex communications lines that enables one-to-one calls and/or one-to-many calls (group calls).


In the walkie talkie manufacturing market we find the PMR446. Their use has spread quite a bit for amateur/home environments, as they are very basic pieces of equipment. But they are also a resource used in work environments, as there is an intermediate range of walkie talkies that can be used.


Both basic and mid-range devices use a technology known as PMR46 and so they are named in stores and catalogues. PMR stands for Personal Mobile Radio 446 MHz, open radio spectrum within UHF, which can be used by any radio amateur with no need to pay a licence fee (this is fully legal in Europe). There are analogue PMR446s (NFM) and digital TDMA (DMR). Their usage is similar to that of US FRS, but as they operate in different frequencies transmitters are not compatible.


They feature a lower range in communications and are highly dependent on the terrain and weather conditions (1.5-3km up to little more than 8-10Km), ease of use, and are lightweight. They have clear sound and dual power (NiMH rechargeable batteries or AA alkaline lithium batteries), can be equipped with a charge base, backlit screen and feature an attractive compact design.


When we talk about using a PMR466, this entails having a unit or they also come in packs of 4 or 6 (with full compatibility amongst them). Some may include a hands-free kit as accessory for better handling and increased functionality; SCAN function and IP protection. They operate in 8 or 16 channels plus 121 privacy codes (subtones). Adjustment of these kinds of walkie talkies enables a maximum of emission of 0.5W (500W) PIRE.


A more professional range of walkie talkies is available in order to cater to the most demanding work environments. This range requires the use of a licence in order to be used with a VHF and/or UHF frequency code (for example: the police, fire brigade, ambulances, security companies, civil protection…). They do not allow intrusion from undesired third parties in communications, which offers higher security, assurance and privacy levels; higher range over longer distances thanks to the use of relays, higher number of channels and very high sound quality.


In view of the fact that the analogue and digital worlds live side by side, there are both types of walkie talkies in the professional range. Amongst them worth noting are devices featuring a high degree of specialization such as ATEX (for explosive atmospheres like air mixed with mist, vapours and gases) and TETRA (featuring more advanced encryption and protection systems). These types of walkie talkies have a high IP protection, customizable buttons for speedier, programmed communications, universal charging and battery systems and CTCSS and DCS tones enabling us to choose what signals will be heard and which will not.


Radio communications under licence may take us to the fascinating field of radio amateurs, a service provided by the International Telecommunication Union. Although this matter is outside the scope of this article it is advisable to provide information on their existence as it allows open access to all bands provided by the IARU (International Amateur Radio Union). Radio amateurs have been allocated several segments within the radio-electrical spectrum. These are the so-called Radio Amateur Bands or Bands allocated to the Amateur Service. Suffice to say that having an operator diploma, a radio amateur approval from the Administration and a station licence are the requirements for making use of an owned communication station.


But there is also the so-called Citizen Band (CB) o Local Band, an unlicensed communication service through two-way radio available to all citizens. This band is also known as the 11-metre band (wave length corresponding to the 27 MHz frequency) and located –within the radio-electrical spectrum within frequencies between 26,900 kHz and 27,400 kHz approximately. The Citizen Band is divided into channels or fixed frequencies, starting from channel 1 (26,965 kHz) up to channel 40 (27,405 kHz). One of the trades using CB27 equipment more intensively -with handy devices, mobile devices and base devices available- are long-distance truck drivers.


Another way we may use –although hardly implemented at present- our mobile phone is to transform it into a walkie talkie through the PoC (Push to talk Over Cell phone) service, which makes use of telephone networks through the standard VoIP protocols.


And last, as most relevant and highly widespread option within the audiovisual industry is the so-called –generically- as the intercom – talk back. Setup of this highly popular solution is normally based on wired installations combining a base station with external stations (remote desktop stations, also known as desk stations) that in turn receive connectivity with the various communication spots, also called belt packs.


The base station, together with the external stations, is the communications hub in fixed installations (such a TV set, a theatre, an auditorium…). Line intercommunication (two-wire, shared) may be found, as well as others using a digital array or equipped with IP technology, turning it into a smart remote station.


AS for belt packs, these are autonomous units (wired or wireless) equipped with a microphone, a headset, volume controls for hearing and talking and a call alert LED. There are multiple types of headsets: open or closed; for one or two ears, and with a condenser or electrect microphone (headset).


The huge advantages of intercom – talk back systems are: full duplex (two-way conversations), immediate, simultaneous, continuous communication without any licensing or communication costs associated, work with several different channels that enable creation of groups (with the possibility of choosing between talk, broadcast to all or mute channels); HD voice (7kHz broadband); two-thread and four-thread operation, broadcast (XLR 3) connectivity, 16-bit DSP technology, 48 kHz audio processes involving 24 bits/sample; externally monitored listening. Furthermore, IP-based intercoms feature setup and monitoring software along with compliance with the AES67 standard for audio streaming and AoIP sources (such as Cobranet, Dante, Ravenna, LiveWire or Q-LAN…), SMPTE 2110 protocol, balancing, non-balanced digital input or S/PDIF.


As for wireless intercom systems, there are both analogue and digital types at present, though manufactures and users are increasingly choosing the latter. In this regard, it must be said that digital wireless allows from 1.9 GHz to operating on the so-called ISM band -ranging from 2.4 GHz to 2.48 GHz (three RF channels)- or on the unlicensed 5 GHz UNII band (up to fifteen RF channels). Very important is the capability of the base station to extend coverage through the number of relays with which it can be connected.


Quoting American actor Chris Hardwick: “We are not in the information age an longer. We are in the information management age instead.” All systems and technologies described above are an essential channel in the communications scene. Very often we rely on the proper operation of every single one of them, but we cannot omit in this article the fact that the way they are used is important as well. We all perfectly know that technical failures or interference may occur in the channel, so we must have assurance that some of the other factors intervening in the communications process will be efficient.


A key one is the need of raising awareness in both issuer and receiver about message, context and the way of using the technical means –the channel- through some advice in order to strive for efficiency from the outset, so:


• Only messages understood at the first try are efficient.
• Use brief, specific messages.
• Use standard orders and protocols approved by the set of professionals, thus avoiding customization of messages (communications tuning).
• Intercommunication systems and devices are not toys for personal use and their proper operation is a need, knowing all their functions and capabilities handed over issuers and receivers by the relevant manufacturers.
• Intercommunication means that everything is being heard, so we must avoid any messages out of the professional context giving rise to such communication.
• Conversations must be simple, clear, and decisive; no hurry whenever the legibility of the message sent from talker to listener is crucial.
• Avoid dissemination of orders that are mistaken or just made up, which may cause doubts and/or false communications.
• Do not transmit any information that may hurt the sensitivity of the various users being interconnected. Avoid any conflict issues (politics, religion, sports, gossip, matters relating trade unions…).
• Be careful with the tone of communication. Always adopt a normal, soft, conciliatory tone that conveys calmness and confidence.
• Know how to listen and have in mind who will receive the message being given, as many times there will be several receivers. This entails not interrupting communication processes.
• Do not leave communication lines open if absent. Always take care to let everyone else know we are no longer present or using the communication system.
• Always reply if you are required to do so in the communication process in accordance with the message and coding protocols put in place.


In sum, the importance of communication is everyone’s responsibility, in order to remove or avoid any elements, phenomena, variables and situations that do not favour a constant, clean and efficient flow. This is known as noise (both technical and in communications).


Workflows are successful thanks to the success of a communication adapted to the technical means known to be required. And let us not forget some recommendations such as checking the power supply of the intercom and talk back tools (batteries or network) check buttons, microphones and listening devices, tweak parameters such as power and volume, carry out some previous tests and determine the role of each participant in the communication process.


By CARLOS MEDINA, Expert and Advisor on Audiovisual Technology

Sam Price-Waldman, a
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