Introduction; What Distinguishes Business Telephony? - Polycom SoundStation VTX1000 Reference Manual

THE "BRAIN" MODEL OF INTELLIGIBILITY IN BUSINESS TELEPHONY

Introduction

There are times when there is no substitute for being understood on the telephone. Well
before 1937, the limitations of the telephone in accurately conveying speech were known.
Irregular and limited bandwidth, noise, variations in end-to-end loudness, sidetone and
distortion had all been identified as contributors to degradation of the spoken word. In
1910, Campbell performed experiments in which he found 59 percent accuracy when
words were called over the telephone, as compared to 96 percent through open air.
abilities of the telephone as an efficient and accurate channel for human speech have
always been regarded with a bit of a wink and a chuckle, tolerated due to a common
understanding that it is the best available.
Despite modern digital trunking and switching technology, this remains an everyday
problem. Why? Analog loop lengths, building wiring, variable line equalization
characteristics, poor handset and speakerphone designs, mixed networks, noise in
conference rooms, paper shuffling, pen tapping, fan noise, and a host of other issues are
still with us, even here in the digital age.
This paper discusses these issues and presents the "BRAIN" model of critical elements in
business telephony. We show how their mutual dependencies can be used to improve
telephone and audio system performance, and how contemporary systems can produce
direct benefits to clear communications.

What Distinguishes Business Telephony?

In business, the critical role of the telephone is magnified for a number of reasons.
Consider the following characteristics of business telephony.
• Time is often in more demand than in personal telephony, which makes
misunderstandings and "can you repeat that?" more frustrating. Meetings have
fixed lengths, so lost time is irretrievable.
Polycom, Inc.
"I am in susquehanna jail. Susquehanna.
S — u — s — q —
'Q'! 'Q,' you know, the thing you play billiards with.
Billiards. B — i — l — l — i —
No, 'L', for 'Larynx!'
L — a — r — y — n —
No! Not 'M'! 'N'!!!
'N', as in 'Neighbor'! N — e — i ..."
---Eric Blore, in jail and on the phone to Fred Astaire in "Shall We Dance," 1937
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