Fix and simplify the power estimation in the IntelligibilityEnhancer

webrtc/modules/audio_processing/noise_suppression_impl.cc

Index: webrtc/modules/audio_processing/noise_suppression_impl.cc
diff --git a/webrtc/modules/audio_processing/noise_suppression_impl.cc b/webrtc/modules/audio_processing/noise_suppression_impl.cc
index 400e8e449d12d35c1bc193a427d326d7ff7858eb..dbfe1c4c3755df2c2c8075aecad239ee8be4fde0 100644
--- a/webrtc/modules/audio_processing/noise_suppression_impl.cc
+++ b/webrtc/modules/audio_processing/noise_suppression_impl.cc
@@ -177,15 +177,17 @@ std::vector<float> NoiseSuppressionImpl::NoiseEstimate() {
   rtc::CritScope cs(crit_);
   std::vector<float> noise_estimate;
 #if defined(WEBRTC_NS_FLOAT)
+  const float kNormalizationFactor = 1.f / (1 << 15);
   noise_estimate.assign(WebRtcNs_num_freq(), 0.f);
   for (auto& suppressor : suppressors_) {
     const float* noise = WebRtcNs_noise_estimate(suppressor->state());
     for (size_t i = 0; i < noise_estimate.size(); ++i) {
-      noise_estimate[i] += noise[i] / suppressors_.size();
+      noise_estimate[i] += kNormalizationFactor *
+          noise[i] / suppressors_.size();
     }
   }
 #elif defined(WEBRTC_NS_FIXED)
-  const float kNormalizationFactor = 1.f / (1 << 8);
+  const float kNormalizationFactor = 1.f / (1 << 23);
   noise_estimate.assign(WebRtcNsx_num_freq(), 0.f);
   for (auto& suppressor : suppressors_) {
     const uint32_t* noise = WebRtcNsx_noise_estimate(suppressor->state());