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5.17.2 Using Noise Cancellation
When using the noise cancellation feature, observe the following:
•
Verify
NOISE CANCELLATION
is enabled (see Section 5.17.1).
•
Talk within two (2) inches of the primary microphone (see Figure 5-5).
•
Ensure the primary and secondary microphones are not covered. See Section 5.17.4 for more
information on the primary and secondary microphones.
•
Speak clearly, loudly, and with authority.
•
In noisy environments, it is o.k. to yell into the radio. The radio can handle loud input levels.
Figure 5-5: Using Noise Cancellation
5.17.3 The Effect of Distance from the Microphone
Unlike a normal microphone system, noise cancellation makes the level of your voice diminish
quickly as you move away from the radio. The radio starts to see your voice as surrounding noise.
Whereas you may be comfortable speaking up to a foot away under normal operation, noise
cancellation requires that you hold the radio close.
5.17.4 Primary versus Secondary Microphone
5.17.4.1 Without a Speaker Microphone Attached
The primary microphone is located on top of the radio and the secondary is on the bottom of the
radio (refer to Figure 5-1 for microphone locations).
5.17.4.2 With a Speaker Microphone Attached
When a speaker microphone is attached, the radio electronically switches over to use the radio’s
top left microphone as secondary. The microphone on the attached speaker microphone becomes
primary.
5.17.5 When using a Self-Contained Breathing Apparatus (SCBA) Mask
When using an SCBA mask, the primary microphone can be held directly against the voice port.
If the SCBA has a voice amplifier, the same rule applies. Ensure that the secondary microphone
is uncovered. If possible, point the secondary microphone toward the noise source.
