Specifications

MIL-STD-1472E
5.3,4,4.2 Acoustic environrnen(. Established signals shal! be used, provided they are
conmatible with the acoustic environment and the requirements specified herein for the voice
communication system. Standard signals shall not k used to convey new meanings.
5.3.4.5 Masking
5.3.4.5.1 Other critical channels. Audio warning signals shall not interfere with any other
critical fimctions or warning signals, or mask any other critical audio signals.
5.3.4.5.2 Setmrate channels. Where a warning signal delivered to a headset might mask another
essential audio signal, separate channels may be provided to direct the warning signal to one ear and
the other essential audio signal to the other ear, When required by operating conditions, this dichotic
presentation may also alternate the two signals from ear to ear.
5.3.5 Verbal warniw signals.
5.3.5.1 Nature of signals Verbal warning signals shall consist of
a, an initial alerting (non speech) signal to attract attention and to designate the general problem,
and
b.
a brief standardized verbal message to identi~ the specific condition and to suggest
appropriate action.
5.3.5.2 Intensity. Verbal alarms for critical functions shall be not less than 20 dB above the
speech interference level at the operating position of the intended receiver.
5.3.5.3
vocalcderia-
5.3.5.3.1 Type
of voice. The voice shall be distinctive and mature.
5.3.5.3.2 Delivcrv stvle. The messages shall be presented in a formal, impersonal manner.
5.3.5.4
sPeec
h Processing. Verbal warning signals shall be processed only when necessary to
incnmse or presewe intelligibility, such as by increasing the strength of consonant sounds relative to
vowel strength. Where a signal must be relatively intense because of high ambient noise, peak-
clipping (see MIL-HDBK- 1908) may be used to protect the listener against auditory overload.
5.3.5.5 Message content. Word selection priority shall be intelligibility, aptness, and
conciseness, in that order.
5.3.5.6 Critical warnings and Priorities.
5.3.5.6.1 Critical wamin~ simm.ls. Critical warning signals shall be repeated with not more than
a 3-seccmd pause between messages until the condition is corrected or overridden by the crew.
s,s. s .6.2 Message Priorities. A priority system shall k established to ensure tha[ higher
criticality messages ovcrzide the presentation of lesser priority messages. If two or more incidents m
malfunctions occur slmukmeousl y, the message ha~’mg the h!ghcr pmonty shall he gl ven tIrst. i he
r~m~jnjng messngef shnl!
fn!lnw in nrder nf prinri~
In the event of a
completr sllhsysrem t%illm= the
wstcm shall integrate previous rne.ssages via electronic gating and repori the sulwvstem rather than the
,
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