Most PA / 'Tannoy' systems we see today employ dedicated microphones for making their voice announcements. Microphones have been used in this way for many, many years, providing a quality and reliable means of system input.
With the ubiquitous use of telephones we now see so freely available, it is possible to interface these to most existing or new PA / 'Tannoy' systems with the introduction of a Telephone Interface Unit. Primarily, this unit does exactly what it says, it provides an interface for someone using a telephone to make announcement / paging calls from the PA / 'Tannoy' system. There are a number of benefits and capability improvements provided by telephone interface units when used in this way, when compared to traditional microphones.
By adding a telephone interface to a PA / 'Tannoy' system, we have introduced the ability to make announcements and paging calls from telephones. Telephones are not special or dedicated functionally in the way that microphones are. They are regular telephones, that might be local to the building, the site, or in fact they can be anywhere, national or even international. With this location independence, we find customers realising benefit and capability improvements such as:
Use of the PA / 'Tannoy' system with first aid / response policy (use telephones to call for help or inform)
Make announcements / paging calls from places that are impractical or impossible to do so by using regular microphones (eg. between buildings or sites, roads, towns..... places microphones cannot reach).
No expensive microphone equipment installation or cabling, also simplifies adds, moves and changes.
Telephone Interface Units can provide 'recorded' announcements. Release the announcement message only when you are happy.
Avoid audio 'feedback' between microphones and speakers. Most microphones send announcement messages 'live'. If a speaker is closeby, then an audio loop can be created. Audio loops can be avoided by using recorded announcements through the telephone interface (note: not all telephone interface units have this capability, please ask for more details).
Some telephone interfaces offer the capability option of pre-recording announcements / paging calls before they are released to the PA / Tannoy system for broadcast. This popular option allows the person making the announcement to re-record the message, and only release for broadcast when they are happy. Pre-recorded announcement capability provides confidence to the user and also avoids audio 'loop' issues (eg. a live announcement made within 'ear-shot' of a speaker).
SIP VoIP telephones can be used to make announcements. Running SIP firmware, IP Audio 'decoder' unit/s register for service from the host IP telephony system. The decoder unit/s can be used to interface to regular amplified Public Address (PA) / 'Tannoy' equipment. Alternatively (or additionally), decoder/amplifier unit/s (contain an integrated amplifier), can be used to directly connect any standard 8ohm speaker/s - this is a particularly useful option where only one or few speakers are required.