Framingham, MA 01701-9168
SIZE
A
FSCM
32108
CLASS
RF
DWG NO.
273139
SHEET
25 of 25
REV.
01D
Harmonic Distortion
The harmonic distortion of the earphone assembly in Low Power and Intercom
Modes shall not exceed 5% for a 0± 0.1dBV input at 500 Hz and it shall not
exceed 10% with the input adjusted for an output of 100dB SPL at 500 Hz and
then swept from 300 Hz to 4500 Hz. The harmonic distortion of the earpohone
assembly in Unpowered Mode shall not exceed 5% for a -6± 0.1dBV input at 500
Hz and it shall not exceed 10% with the input adjusted for an output of 94dB SPL
at 500 Hz and then swept from 300 Hz to 4500 Hz.
Talk Through Circuit (TTC)
The headset shall incorporate a talk-through circuit to permit monitoring of the
ambient sound field and direction finding. When mounted on a simulated real
head fixture (mannequin), at 22
o
C, 50% RH the TTC shall produce gain of 0±
6dB when measured in the 500 Hz octave band and an acoustic frequency
response within 0± 8dB when measured in one octave frequencies between 300
and 4500 Hz and corrected for diffuse field response of the fixture.
The talk-through circuit shall limit direct earcup output to between 86dB(A) SPL
maximum and 72dB(A) minimum with the output corrected for the diffuse field
response of the fixture.
Boom Microphone Sensitivity
The dynamic boom microphone sensitivity shall be -56±4 dBm @ 1kHz re. 103dB
SPL.
