diff --git a/firmware/application/tone_key.cpp b/firmware/application/tone_key.cpp
index a208c96e1..5b5aed6ff 100644
--- a/firmware/application/tone_key.cpp
+++ b/firmware/application/tone_key.cpp
@@ -104,8 +104,30 @@ void tone_keys_populate(OptionsField& field) {
 	field.set_options(tone_key_options);
 }
 
-float tone_key_frequency(const uint32_t index) {
+float tone_key_frequency(const tone_index index) {
 	return tone_keys[index].second;
 }
 
+std::string tone_key_string( tone_index index ) {
+	if( index < 0 || (unsigned)index >= tone_keys . size() )
+		return std::string( "" ); 
+	return tone_keys[ index ] .first ;
+}
+
+tone_index tone_key_index_by_string( char *str ) {
+	if( !str )
+		return -1 ;
+	for( tone_index index = 0 ; (unsigned)index < tone_keys . size() ; index ++ )
+	{
+		if( tone_keys[ index ] . first . compare( str ) >= 0 )
+			return index ;
+	}
+	return -1 ;	
+}	
+
+/* tone_index tone_key_index_by_value( int32_t freq )
+{
+	return -1 ;	
+} */
+
 }
diff --git a/firmware/application/tone_key.hpp b/firmware/application/tone_key.hpp
index 70438d860..0f5e4f243 100644
--- a/firmware/application/tone_key.hpp
+++ b/firmware/application/tone_key.hpp
@@ -30,12 +30,18 @@ using namespace ui;
 
 namespace tonekey {
 
+typedef int16_t tone_index ;
+
 using tone_key_t = std::vector<std::pair<std::string, float>>;
 
 extern const tone_key_t tone_keys;
 
 void tone_keys_populate(OptionsField& field);
-float tone_key_frequency(const uint32_t index);
+float tone_key_frequency(const tone_index index);
+
+std::string tone_key_string( const tone_index index );
+tone_index tone_key_index_by_string( char *str );
+// tone_index tone_key_index_by_value( int32_t freq );
 
 }