diff --git a/speechx/speechx/frontend/audio/audio_cache.h b/speechx/speechx/frontend/audio/audio_cache.h
index 45498e46f2360dc32303eaeec8168c4f6648c38d..e31a8aeb57e2ec0d6e9d0d101767e2073ba4b9f3 100644
--- a/speechx/speechx/frontend/audio/audio_cache.h
+++ b/speechx/speechx/frontend/audio/audio_cache.h
@@ -30,7 +30,8 @@ class AudioCache : public FrontendInterface {
 
     virtual bool Read(kaldi::Vector<kaldi::BaseFloat>* waves);
 
-    // the audio dim is 1, one sample, we return size_ instead.
+    // the audio dim is 1, one sample, which is useless, 
+    // so we return size_(cache samples) instead.
     virtual size_t Dim() const { return size_; }
 
     virtual void SetFinished() {
diff --git a/speechx/speechx/frontend/audio/feature_common.h b/speechx/speechx/frontend/audio/feature_common.h
index 0763f0122ff22551a0ed7e2ce7530893f35a2a50..e03634d35a0723ae5a2f659e4a9732787106942c 100644
--- a/speechx/speechx/frontend/audio/feature_common.h
+++ b/speechx/speechx/frontend/audio/feature_common.h
@@ -25,7 +25,7 @@ class StreamingFeatureTpl : public FrontendInterface {
     typedef typename F::Options Options;
     StreamingFeatureTpl(const Options& opts, 
                         std::unique_ptr<FrontendInterface> base_extractor);
-    virtual void Accept(const kaldi::VectorBase<kaldi::BaseFloat>& inputs);
+    virtual void Accept(const kaldi::VectorBase<kaldi::BaseFloat>& waves);
     virtual bool Read(kaldi::Vector<kaldi::BaseFloat>* feats);
     
     // the dim_ is the dim of single frame feature
@@ -51,4 +51,4 @@ class StreamingFeatureTpl : public FrontendInterface {
 
 }  // namespace ppspeech
 
-#include "frontend/audio/feature_common_inl.h"
\ No newline at end of file
+#include "frontend/audio/feature_common_inl.h"
diff --git a/speechx/speechx/frontend/audio/feature_common_inl.h b/speechx/speechx/frontend/audio/feature_common_inl.h
index 0199ab4116df363863588885812b425425e2bb17..a482ef557f65f2ecf4d94179841aa8fcae1e58d6 100644
--- a/speechx/speechx/frontend/audio/feature_common_inl.h
+++ b/speechx/speechx/frontend/audio/feature_common_inl.h
@@ -25,8 +25,8 @@ StreamingFeatureTpl<F>::StreamingFeatureTpl(const Options& opts,
 }
 
 template <class F>
-void StreamingFeatureTpl<F>::Accept(const kaldi::VectorBase<kaldi::BaseFloat>& inputs) {
-    base_extractor_->Accept(inputs);
+void StreamingFeatureTpl<F>::Accept(const kaldi::VectorBase<kaldi::BaseFloat>& waves) {
+    base_extractor_->Accept(waves);
 }
 
 template <class F>
@@ -92,4 +92,4 @@ bool StreamingFeatureTpl<F>::Compute(const kaldi::Vector<kaldi::BaseFloat>& wave
     return true;
 }
 
-}  // namespace ppspeech
\ No newline at end of file
+}  // namespace ppspeech