What is a discussion microphone? Part 2

What is a discussion microphone? How is it different from a conventional microphone?  Part 2. Mark Kisby continues his explanation… (missed Part 1? click here)

Conference, discussion or ‘push to talk’ microphones provide the best conference audio solution for speech reinforcement. Though sometimes not the best in absolute sound quality, it is the ability for the microphone to be controlled by both delegate and sound technician that ensures every word is heard.

Boardroom discussion microphones

Discussion microphones set for a boardroom style conference

For this reason conference microphones are particularly suited to the recording of meetings, councils and parliaments and the provision of the ‘original’ feed to a simultaneous interpretation system.

In these applications the aims is to have as few microphones ‘live’ or ‘on’ at any one time, each ‘live’ microphone adds more back ground noise to the audio feed.

The standard operation of a sound desk with just 6 conventional microphones on a top table is to leave all 6 microphones live (but set to a low volume) so if someone does speak the technician need only increase the level of a microphone. This allows at least some audio, albeit low level to begin with, to be heard which is better than nothing. This is because the technician does not know who is going to speak next and the speaker is unable to make their microphone live independently of the technician. There are two main reasons why this is not acceptable in a recording or for simultaneous interpretation.

Firstly the delay in a delegate speaking and in the microphone becoming live, as the technician recognises which microphone is in use and increases its level,  introduces a pause into which whole sentences can disappear and critical meaning can be lost. Conference microphones can be operated by the speaker directly so eliminating this delay in making the microphone live or louder. This allows a freer flow of dialogue to take place without a word being lost. This is critical in the recording of important meetings and in the original language feed for simultaneous interpreters.

Secondly by having so many partially live microphones live you are introducing unwanted and distracting background noise into the audio. This is often not recognised by the delegates or by the technician who generally listen to the audio via the PA in the room where these noises are already present. However other users, e.g. interpreters, listen to the proceedings via headphones so they are very ‘close’ to the audio and can clearly hear the rustle of paper or the pouring of water. This unwanted audio is very distracting and can mask important elements of the speech.

With a conference microphone system you have the capability to control and help eliminate these spurious sounds without losing the critical audio by only having one or two microphones live at any one time.

The other added advantage is that it is possible for a system to extend to include  10 – 100 – 1000 participants so making the discussion microphone ideal for use in council chambers, parliaments and general meeting rooms.

The advantages in using discussion microphones or discussion systems are very clear (especially the audio!).

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