diff --git a/src/Tuner.cpp b/src/Tuner.cpp
index 1970487..4950420 100644
--- a/src/Tuner.cpp
+++ b/src/Tuner.cpp
@@ -58,6 +58,8 @@ Tuner::Tuner()
 	note = octave = 0; 
 	found = false;
 	count_found = count_not_found = 0;
+	nb_sample_running = 0;
+	note_found = octave_found = -1;
 
 	if (filename_record) file_record.open(filename_record);
 
@@ -98,7 +100,9 @@ Tuner::~Tuner()
 	delete high_filter;
 	delete cross;
 	delete recorder;
+	delete probe;
 	delete scale;
+	delete temperaments;
 }
 
 void Tuner::Start()
@@ -208,25 +212,30 @@ void Tuner::AudioAnalyse(const int16_t *ptr, int nb_frame)
 {
 	nb_sample_running += nb_frame;
 
+	// record in file is needed
 	if (filename_record && file_record.is_open()) file_record.write((char*) ptr, nb_frame * sizeof(int16_t));
 
+	// compute every audio frame
 	while (nb_frame--) ComputeFrame(*ptr++);
 
+	// update frequency
 	if (freq != cross->Freq()) {
 		freq = cross->Freq();
 		freqChanged();
-
-		if (freq) {
-			int n, o;
-			double d;
-			n = scale->FindNote(freq, o, d);
-			SetFound(n, o, d);
-		}
-		else { // no freq
-			SetNotFound();
-		}
 	}
 
+	// find note, octave, deviation
+	if (freq) {
+		int n, o = 0;
+		double d = 0;
+		n = scale->FindNote(freq, o, d);
+		SetFound(n, o, d);
+	}
+	else { // no freq
+		SetNotFound();
+	}
+
+	// prevent screen blanking
 	if (nb_sample_running >= nbSamplePreventRunning && running) {
 		nb_sample_running = 0;
 		blank_prevent(true);
diff --git a/src/audio/LinearFilter.hpp b/src/audio/LinearFilter.hpp
index 975c09f..c558906 100644
--- a/src/audio/LinearFilter.hpp
+++ b/src/audio/LinearFilter.hpp
@@ -27,11 +27,21 @@ template<typename A> class LinearFilter {
 	double *backx, *backy;
 
 	public:
+	/**
+	 * filter constructor
+	 *
+	 * @param order Order of filter (2 = biquads)
+	 * @param a Array of a coefficiants
+	 * @param b Array of b coefficiants
+	 */
 	LinearFilter(int order, double *a, double *b);
 	~LinearFilter();
 
+	/// Clear audio stream
 	void Clear();
+	/// Compute one audio sample
 	A operator() (A x);
+	/// Compute an audio buffer in place
 	void operator() (A *ptr, int nbFrame);
 };
 
diff --git a/src/audio/ZeroCross.hpp b/src/audio/ZeroCross.hpp
index 69a5f97..9314b0b 100644
--- a/src/audio/ZeroCross.hpp
+++ b/src/audio/ZeroCross.hpp
@@ -53,10 +53,14 @@ template<typename sample_t> class ZeroCross {
 
 	public:
 	ZeroCross(const Config &config);
+	/// analyse audio buffer
 	double operator() (sample_t *ptr, int nbFrame);
+	/// analyse one audio sample
 	void operator() (sample_t v);
 
+	/// Clear stream analyse
 	void Clear();
+	/// Get current frequency computed
 	double Freq();
 };
 
diff --git a/src/scale/Temperaments.cpp b/src/scale/Temperaments.cpp
index ae0c989..1285fc2 100644
--- a/src/scale/Temperaments.cpp
+++ b/src/scale/Temperaments.cpp
@@ -105,8 +105,11 @@ bool Temperaments::SetTemperament(unsigned int index)
 		qDebug() << __func__ << "index" << index << "out of range";
 		return false;
 	}
-	current = index;
-	return CheckoutTemperament(list[current]);
+	if (CheckoutTemperament(list[index])) {
+		current = index;
+		return true;
+	}
+	return false;
 }
 
 bool Temperaments::SetTemperament(const QString name)
diff --git a/src/scale/Temperaments.hpp b/src/scale/Temperaments.hpp
index 6214eb3..e2bb9ed 100644
--- a/src/scale/Temperaments.hpp
+++ b/src/scale/Temperaments.hpp
@@ -42,14 +42,17 @@ class Temperaments {
 	std::vector<temp_t> list;
 	double notes[nb_notes];
 
+	/// Check data files in directory
 	void GetDir(const QString & dirname);
+	/// Check temperaments in file
 	void CheckFile(const QString & filename);
+	/// Load given temperament
 	bool CheckoutTemperament(const temp_t & temperament);
 
 	public:
 	/// constructor with dir name to find data files
 	Temperaments(const QString & dirname);
-	~Temperaments();
+	~Temperaments() {}
 
 	/// set current temperament
 	bool SetTemperament(const QString name);