DEAF AND DUMB
One of the core laws of information transfer theory is as follows: Humans read faster than they can listen, but speak faster than they can write. Voice mail vs. E-Mail provides an excellent illustration of this asymmetry: It’s quite a bit faster to send twenty voice mails than it is to type out twenty emails – but it’s much faster to read twenty emails than to listen to twenty people’s voice messages, especially if there’s anything important in that message that needs to be subsequently written down.
Visually organized systems, such as documents and web pages, end up being more complex than a simple stream of spoken phrases to generate, but once generated can be skimmed quickly for areas of relevance to the reader which then may be focused on. Notably, the message is not time dependent-the words stay where they were as the reader moves onto another segment.
By sharp contrast, the spoken word is nothing more than a stream of vibrations in the air-the stream might be repeated, but it exists as an understandable entity only because of our short-term memories. As soon as a word is spoken, it disappears, and can only be retransmitted on demand, not simply referred back to with a jump of the eye.
Thus the prime flaw with Interactive Voice Response, or IVR: It must speak everything-slowly, linearly–and IVR is left struggling with a painfully slow method for providing feedback to its users.
And yet, Since telephones are built to carry speech, one might assume. But sound is only the most efficient input to information systems when our spur-of-the-moment phrasings of a specific request, or even our standardized vocalizations of a given demand, can be understood and interpreted among many other possibilities.