PS-REP-199 · r1
REPRESENTATION
OBSERVED
ENGAGED
SEVERITY THE DEVICE ALLOWS
The gap between calm and urgent is only as wide as the thing playing it.
01 DEFINITION
Condition in which a difference in seriousness is carried by sound or vibration and one design is issued to devices whose ability to reproduce it varies, so the distance between the ordinary and the urgent is set by whatever happens to be playing it.
02 CONDITIONS
UNCERTAINTY
MISSING
What the receiving device can actually render is not known where the scheme is designed.
TIME PRESSURE
SHORT
The distinction has to land in the moment it sounds or it does not land.
ERROR ASYMMETRY
ASYMMETRIC
An urgent signal heard as routine and a routine one heard as urgent cost differently.
OPERATOR STATE
CONCURRENT
The person is doing something else and has only the sound to grade it by.
03 WHERE IT APPEARS
MEDICALOne alarm scheme is issued to devices whose sounders differ, so the graded difference is not the same everywhere.
MOBILITYWarning chimes and seat feedback are specified once and reproduced by hardware of varying quality.
INDUSTRIALPlant sounders of different age carry one scheme of seriousness that some of them cannot express.
PUBLIC SERVICEPublic address of different quality carries one scheme of urgency across sites.
MANUFACTURINGStation signals designed as a graded set are fitted to equipment that renders the grades unevenly.
CONSTRUCTIONSite warnings intended as a hierarchy are carried by whatever equipment is on that site.
04 WHAT AEON WORKED THROUGH HERE
A calm signal and an urgent one were designed as a pair, and the pair was issued to speakers and motors of very different quality. On some of them the two were the same event. The work went into which part of the difference does not depend on the hardware — pattern and repetition rather than timbre and force — so that the hierarchy survived the poorest thing carrying it.
What stays unresolved is where the hierarchy actually lives — designing to the weakest device flattens it everywhere, and designing to the strongest leaves the urgent indistinguishable from the routine on whatever the person happens to be near.