AS3460
Wind Noise Detection
Demo Kit Manual
• PUBLIC
UG000480
• v3-00 • 2021-Nov-08
126
│ 122
15.2
Operation
Wind can create very loud sound pressure at the outer microphone positions of the headphone (FF &
Speech microphone). This can lead to digital signal clipping inside the AHE engine and audible
distortions. To prevent these audible distortion artifacts the wind noise suppression uses the two
outside microphones to detect wind. Once wind is detected the FF and Voice microphone gains will be
ramped down to avoid clipping. The FB gain will stay untouched since the FB microphone is
positioned inside the headphone and thus not exposed to wind.
From the two outside microphones a wind metric is permanently calculated that describes the
probability of wind events. The wind metric value can be observed by using a watcher in FleX. Two
thresholds can be set to determine at which wind metric level the wind suppression will activate and at
which level it will fully ramp down the FF and Voice gains to the maximum suppression. These are the
“low wind threshold” and the “high wind threshold” and the maximum suppression level is set by
“Preset X fully suppressed gain”, which can be individually set for each preset.
For example:
If Low Wind Threshold = 300, then when the wind metric is lower than 300 then there is no
suppression (0%). If High Wind Threshold = 600, then when the wind metric is greater than 600 the
suppression applied is the maximum configured (100%) for the preset and voice paths. The amount of
suppression varies linearly between the two above thresholds, so at a wind metric level of 450, 50% of
the configured suppression is applied.
Figure 136:
Wind Noise Detection Parameters in FleX
