The signal to noise ratio describes the strength of a desired information signal against the level of unwanted background signal. That is, the clarity of the overall message in a presentation, considering all aspects of that presentation. Signal to noise ratio describes effectively how easy it is for the audience to clearly determine the message from everything being broadcast.
In the message (p1) it is essential that there is a clear, simple and memorable message that the audience can take away. It is from this that the audience can rebuild the presentation having left the event. If the presenter does not make this clear at the beginning, during the presentation and at the end, the extraneous noise of the presentation will overload the audience. Large volumes of data without clarity or structure are simple examples. In the message, one must maximise signal.
The purpose of the support media (p2) is to support the message. The media in most presentations adds noise not signal. Media must be simple and clear to avoid conflicting with the spoken message. Complexity of image, data or structure adds noise to the image itself, the sum of which further adds noise to the signal delivered by the presenter. It is unreasonable to expect the audience to apply their own filters to this input. The default action when signal to noise ration is overwhelming is to concentrate on the visual, at the expense of the spoken message. When that signal itself is complex, its own internal signal to noise ratio will overwhelm. As a presenter, one must ensure that the media adds signal, rather than noise.
Even in delivery (p3), there is an issue of signal to noise ratio. A huge presentation screen, displayed onto a complex, organisational background with a tiny, poorly illuminated presenter, increases the noise of the delivery. This is exemplified in the online presentation, where further noise is added by the challenge of watching a presentation on a small screen whilst distracted by one’s surroundings, a mobile phone or concurrent tasks being undertaken. It is essential in delivery that the signal to noise ratio is maximised.
Signal to noise ratio must be actively controlled in construction and delivery of a presentation to ensure clarity of communication for the audience. Construct a clear and memorable message, reduce the complexity of supportive media and maximise the broadcast of delivery to ensure that that the presentation is not lost in the surrounding noise.