diff --git a/src/libespeak-ng/CMakeLists.txt b/src/libespeak-ng/CMakeLists.txt
index 63f0d48c..ffffbd5e 100644
--- a/src/libespeak-ng/CMakeLists.txt
+++ b/src/libespeak-ng/CMakeLists.txt
@@ -54,6 +54,7 @@ if (NOT MSVC)
     "-Wmissing-prototypes"
     "-Wint-conversion"
     "-Wimplicit"
+    "-Wmisleading-indentation"
   )
 endif()
 target_compile_definitions(espeak-ng PRIVATE "LIBESPEAK_NG_EXPORT=1")
diff --git a/src/libespeak-ng/compiledata.c b/src/libespeak-ng/compiledata.c
index 58924808..aa473a96 100644
--- a/src/libespeak-ng/compiledata.c
+++ b/src/libespeak-ng/compiledata.c
@@ -2789,4 +2789,4 @@ static int CalculateSample(unsigned char c3, int c1) {
 	c2 = c2 >> 16; // sign extend
 
 	return (c1 & 0xff) + c2;
-}
\ No newline at end of file
+}
diff --git a/src/libespeak-ng/compiledict.c b/src/libespeak-ng/compiledict.c
index 0fffdde2..9304f4e1 100644
--- a/src/libespeak-ng/compiledict.c
+++ b/src/libespeak-ng/compiledict.c
@@ -320,7 +320,7 @@ char *DecodeRule(const char *group_chars, int group_length, char *rule, int cont
 			}
 			c = ' ';
 		} else if (rb == RULE_ENDING) {
-			static const char *flag_chars = "eipvdfq tba ";
+			static const char flag_chars[] = "eipvdfq tba ";
 			flags = ((rule[0] & 0x7f)<< 8) + (rule[1] & 0x7f);
 			suffix_char = 'S';
 			if (flags & (SUFX_P >> 8))
diff --git a/src/libespeak-ng/dictionary.c b/src/libespeak-ng/dictionary.c
index 8f69ba5d..32ce7de4 100644
--- a/src/libespeak-ng/dictionary.c
+++ b/src/libespeak-ng/dictionary.c
@@ -43,8 +43,8 @@
 #include "synthesize.h"                    // for STRESS_IS_PRIMARY, phoneme...
 #include "translate.h"                     // for Translator, utf8_in, LANGU...
 
-static int LookupFlags(Translator *tr, const char *word, unsigned int **flags_out);
-static void DollarRule(char *word[], char *word_start, int consumed, int group_length, char *word_buf, Translator *tr, unsigned int *flags, int command, int *failed, int *add_points);
+static int LookupFlags(Translator *tr, const char *word, unsigned int flags_out[2]);
+static void DollarRule(char *word[], char *word_start, int consumed, int group_length, char *word_buf, Translator *tr, int command, int *failed, int *add_points);
 
 typedef struct {
 	int points;
@@ -63,7 +63,7 @@ static const unsigned short diereses_list[7] = { 0xe4, 0xeb, 0xef, 0xf6, 0xfc, 0
 // convert characters to an approximate 7 bit ascii equivalent
 // used for checking for vowels (up to 0x259=schwa)
 #define N_REMOVE_ACCENT  0x25e
-static unsigned char remove_accent[N_REMOVE_ACCENT] = {
+static const unsigned char remove_accent[N_REMOVE_ACCENT] = {
 	'a', 'a', 'a', 'a', 'a', 'a', 'a', 'c', 'e', 'e', 'e', 'e', 'i', 'i', 'i', 'i',  // 0c0
 	'd', 'n', 'o', 'o', 'o', 'o', 'o',   0, 'o', 'u', 'u', 'u', 'u', 'y', 't', 's',  // 0d0
 	'a', 'a', 'a', 'a', 'a', 'a', 'a', 'c', 'e', 'e', 'e', 'e', 'i', 'i', 'i', 'i',  // 0e0
@@ -396,7 +396,7 @@ void DecodePhonemes(const char *inptr, char *outptr)
 	unsigned char c;
 	unsigned int mnem;
 	PHONEME_TAB *ph;
-	static const char *stress_chars = "==,,'*  ";
+	static const char stress_chars[] = "==,,'*  ";
 
 	sprintf(outptr, "* ");
 	while ((phcode = *inptr++) > 0) {
@@ -551,7 +551,7 @@ const char *GetTranslatedPhonemeString(int phoneme_mode)
 	char phon_buf2[30];
 	PHONEME_LIST *plist;
 
-	static const char *stress_chars = "==,,''";
+	static const char stress_chars[] = "==,,''";
 
 	if (phon_out_buf == NULL) {
 		phon_out_size = N_PHON_OUT;
@@ -1480,10 +1480,9 @@ static void MatchRule(Translator *tr, char *word[], char *word_start, int group_
 	int n_bytes;
 	int add_points;
 	int command;
-	unsigned int *flags = NULL;
 
 	MatchRecord match;
-	static MatchRecord best;
+	MatchRecord best;
 
 	int total_consumed; // letters consumed for best match
 
@@ -1699,7 +1698,7 @@ static void MatchRule(Translator *tr, char *word[], char *word_start, int group_
 						else
 							failed = 1;
 					} else if (((command & 0xf0) == 0x20) || (command == DOLLAR_LIST)) {
-						DollarRule(word, word_start, consumed, group_length, word_buf, tr, flags, command, &failed, &add_points);
+						DollarRule(word, word_start, consumed, group_length, word_buf, tr, command, &failed, &add_points);
 					}
 
 					break;
@@ -1888,7 +1887,7 @@ static void MatchRule(Translator *tr, char *word[], char *word_start, int group_
 					pre_ptr++;
 					command = *rule++;
 					if ((command == DOLLAR_LIST) || ((command & 0xf0) == 0x20)) {
-						DollarRule(word, word_start, consumed, group_length, word_buf, tr, flags, command, &failed, &add_points);
+						DollarRule(word, word_start, consumed, group_length, word_buf, tr, command, &failed, &add_points);
 					}
 					break;
 				case RULE_SYLLABLE:
@@ -2842,7 +2841,7 @@ int Lookup(Translator *tr, const char *word, char *ph_out)
 	return flags0;
 }
 
-static int LookupFlags(Translator *tr, const char *word, unsigned int **flags_out)
+static int LookupFlags(Translator *tr, const char *word, unsigned int flags_out[2])
 {
 	char buf[100];
 	static unsigned int flags[2];
@@ -2850,7 +2849,8 @@ static int LookupFlags(Translator *tr, const char *word, unsigned int **flags_ou
 
 	flags[0] = flags[1] = 0;
 	LookupDictList(tr, &word1, buf, flags, 0, NULL);
-	*flags_out = flags;
+	flags_out[0] = flags[0];
+	flags_out[1] = flags[1];
 	return flags[0];
 }
 
@@ -2979,14 +2979,15 @@ int RemoveEnding(Translator *tr, char *word, int end_type, char *word_copy)
 	return end_flags;
 }
 
-static void DollarRule(char *word[], char *word_start, int consumed, int group_length, char *word_buf, Translator *tr, unsigned int *flags, int command, int *failed, int *add_points) {
+static void DollarRule(char *word[], char *word_start, int consumed, int group_length, char *word_buf, Translator *tr, int command, int *failed, int *add_points) {
 	// $list or $p_alt
 	// make a copy of the word up to the post-match characters
 	int ix = *word - word_start + consumed + group_length + 1;
 	memcpy(word_buf, word_start-1, ix);
 	word_buf[ix] = ' ';
 	word_buf[ix+1] = 0;
-	LookupFlags(tr, &word_buf[1], &flags);
+	unsigned int flags[2];
+	LookupFlags(tr, &word_buf[1], flags);
 
 	if ((command == DOLLAR_LIST) && (flags[0] & FLAG_FOUND) && !(flags[1] & FLAG_ONLY))
 		*add_points = 23;
@@ -2994,4 +2995,4 @@ static void DollarRule(char *word[], char *word_start, int consumed, int group_l
 		*add_points = 23;
 	else
 		*failed = 1;
-}
\ No newline at end of file
+}
diff --git a/src/libespeak-ng/event.c b/src/libespeak-ng/event.c
index 7f04edc2..8e301eec 100644
--- a/src/libespeak-ng/event.c
+++ b/src/libespeak-ng/event.c
@@ -83,9 +83,15 @@ void event_init(void)
 	pthread_mutex_init(&my_mutex, (const pthread_mutexattr_t *)NULL);
 	init();
 
-	assert(-1 != pthread_cond_init(&my_cond_start_is_required, NULL));
-	assert(-1 != pthread_cond_init(&my_cond_stop_is_required, NULL));
-	assert(-1 != pthread_cond_init(&my_cond_stop_is_acknowledged, NULL));
+	int a_status;
+
+	a_status = pthread_cond_init(&my_cond_start_is_required, NULL);
+	assert(-1 != a_status);
+	a_status = pthread_cond_init(&my_cond_stop_is_required, NULL);
+	assert(-1 != a_status);
+	a_status = pthread_cond_init(&my_cond_stop_is_acknowledged, NULL);
+	assert(-1 != a_status);
+	(void)a_status;
 
 	pthread_attr_t a_attrib;
 
@@ -222,7 +228,7 @@ espeak_ng_STATUS event_declare(espeak_EVENT *event)
 	return status;
 }
 
-espeak_ng_STATUS event_clear_all()
+espeak_ng_STATUS event_clear_all(void)
 {
 	espeak_ng_STATUS status;
 	if ((status = pthread_mutex_lock(&my_mutex)) != ENS_OK)
@@ -352,7 +358,7 @@ static espeak_ng_STATUS push(void *the_data)
 	return ENS_OK;
 }
 
-static void *pop()
+static void *pop(void)
 {
 	void *the_data = NULL;
 
@@ -373,7 +379,7 @@ static void *pop()
 }
 
 
-static void init()
+static void init(void)
 {
 	while (event_delete((espeak_EVENT *)pop()))
 		;
@@ -381,7 +387,7 @@ static void init()
 	node_counter = 0;
 }
 
-void event_terminate()
+void event_terminate(void)
 {
 	if (thread_inited) {
 		my_terminate_is_required = true;
@@ -408,7 +414,9 @@ void clock_gettime2(struct timespec *ts)
 	if (!ts)
 		return;
 
-	assert(gettimeofday(&tv, NULL) != -1);
+	int a_status = gettimeofday(&tv, NULL);
+	assert(a_status != -1);
+	(void)a_status;
 	ts->tv_sec = tv.tv_sec;
 	ts->tv_nsec = tv.tv_usec*1000;
 }
diff --git a/src/libespeak-ng/fifo.c b/src/libespeak-ng/fifo.c
index 0befcbb6..bc5ddf8e 100644
--- a/src/libespeak-ng/fifo.c
+++ b/src/libespeak-ng/fifo.c
@@ -71,15 +71,19 @@ enum {
 	MAX_INACTIVITY_CHECK = 2
 };
 
-void fifo_init()
+void fifo_init(void)
 {
 	// security
 	pthread_mutex_init(&my_mutex, (const pthread_mutexattr_t *)NULL);
 	init(0);
 
-	assert(-1 != pthread_cond_init(&my_cond_command_is_running, NULL));
-	assert(-1 != pthread_cond_init(&my_cond_start_is_required, NULL));
-	assert(-1 != pthread_cond_init(&my_cond_stop_is_acknowledged, NULL));
+	int a_status;
+	a_status = pthread_cond_init(&my_cond_command_is_running, NULL);
+	assert(-1 != a_status);
+	a_status = pthread_cond_init(&my_cond_start_is_required, NULL);
+	assert(-1 != a_status);
+	a_status = pthread_cond_init(&my_cond_stop_is_acknowledged, NULL);
+	assert(-1 != a_status);
 
 	pthread_attr_t a_attrib;
 	if (pthread_attr_init(&a_attrib)
@@ -95,7 +99,9 @@ void fifo_init()
 	pthread_attr_destroy(&a_attrib);
 
 	// leave once the thread is actually started
-	assert(-1 != pthread_mutex_lock(&my_mutex));
+	a_status = pthread_mutex_lock(&my_mutex);
+	assert(-1 != a_status);
+	(void)a_status;
 	while (my_stop_is_acknowledged == false) {
 		while ((pthread_cond_wait(&my_cond_stop_is_acknowledged, &my_mutex) == -1) && errno == EINTR)
 			;
@@ -169,7 +175,7 @@ espeak_ng_STATUS fifo_add_commands(t_espeak_command *command1, t_espeak_command
 	return ENS_OK;
 }
 
-espeak_ng_STATUS fifo_stop()
+espeak_ng_STATUS fifo_stop(void)
 {
 	if (!thread_inited) return ENS_OK;
 	espeak_ng_STATUS status;
@@ -197,7 +203,7 @@ espeak_ng_STATUS fifo_stop()
 	return ENS_OK;
 }
 
-int fifo_is_busy()
+int fifo_is_busy(void)
 {
 	if (!thread_inited) return false;
 	pthread_mutex_lock(&my_mutex);
@@ -206,7 +212,7 @@ int fifo_is_busy()
 	return running;
 }
 
-static int sleep_until_start_request_or_inactivity()
+static int sleep_until_start_request_or_inactivity(void)
 {
 	int a_start_is_required = false;
 
@@ -223,7 +229,6 @@ static int sleep_until_start_request_or_inactivity()
 		i++;
 
 		struct timespec ts;
-		struct timeval tv;
 
 		clock_gettime2(&ts);
 
@@ -233,8 +238,6 @@ static int sleep_until_start_request_or_inactivity()
 		       && errno == EINTR)
 			continue;
 
-		assert(gettimeofday(&tv, NULL) != -1);
-
 		if (err == 0)
 			a_start_is_required = true;
 	}
@@ -242,7 +245,7 @@ static int sleep_until_start_request_or_inactivity()
 	return a_start_is_required;
 }
 
-static espeak_ng_STATUS close_stream()
+static espeak_ng_STATUS close_stream(void)
 {
 	espeak_ng_STATUS status = pthread_mutex_lock(&my_mutex);
 	if (status != ENS_OK)
@@ -293,11 +296,16 @@ static void *say_thread(void *p)
 {
 	(void)p; // unused
 
+	int a_status;
+
 	// announce that thread is started
-	assert(-1 != pthread_mutex_lock(&my_mutex));
+	a_status = pthread_mutex_lock(&my_mutex);
+	assert(-1 != a_status);
 	my_stop_is_acknowledged = true;
-	assert(-1 != pthread_cond_signal(&my_cond_stop_is_acknowledged));
-	assert(-1 != pthread_mutex_unlock(&my_mutex));
+	a_status = pthread_cond_signal(&my_cond_stop_is_acknowledged);
+	assert(-1 != a_status);
+	a_status = pthread_mutex_unlock(&my_mutex);
+	assert(-1 != a_status);
 
 	bool look_for_inactivity = false;
 
@@ -310,7 +318,7 @@ static void *say_thread(void *p)
 		}
 		look_for_inactivity = true;
 
-		int a_status = pthread_mutex_lock(&my_mutex);
+		a_status = pthread_mutex_lock(&my_mutex);
 		assert(!a_status);
 
 		if (!a_start_is_required) {
@@ -323,11 +331,13 @@ static void *say_thread(void *p)
 
 		my_command_is_running = true;
 
-		assert(-1 != pthread_cond_broadcast(&my_cond_command_is_running));
-		assert(-1 != pthread_mutex_unlock(&my_mutex));
+		a_status = pthread_cond_broadcast(&my_cond_command_is_running);
+		assert(-1 != a_status);
+		a_status = pthread_mutex_unlock(&my_mutex);
+		assert(-1 != a_status);
 
 		while (my_command_is_running && !my_terminate_is_required) {
-			int a_status = pthread_mutex_lock(&my_mutex);
+			a_status = pthread_mutex_lock(&my_mutex);
 			assert(!a_status);
 			t_espeak_command *a_command = (t_espeak_command *)pop();
 
@@ -352,23 +362,25 @@ static void *say_thread(void *p)
 			// and waiting for my_cond_stop_is_acknowledged
 			init(1);
 
-			assert(-1 != pthread_mutex_lock(&my_mutex));
+			a_status = pthread_mutex_lock(&my_mutex);
+			assert(-1 != a_status);
 			my_start_is_required = false;
 
 			// acknowledge the stop request
 			my_stop_is_acknowledged = true;
-			int a_status = pthread_cond_signal(&my_cond_stop_is_acknowledged);
+			a_status = pthread_cond_signal(&my_cond_stop_is_acknowledged);
 			assert(a_status != -1);
 			pthread_mutex_unlock(&my_mutex);
 
 		}
 		// and wait for the next start
 	}
+	(void)a_status;
 
 	return NULL;
 }
 
-int fifo_is_command_enabled()
+int fifo_is_command_enabled(void)
 {
 	return 0 == my_stop_is_required;
 }
@@ -413,7 +425,7 @@ static espeak_ng_STATUS push(t_espeak_command *the_command)
 	return ENS_OK;
 }
 
-static t_espeak_command *pop()
+static t_espeak_command *pop(void)
 {
 	t_espeak_command *the_command = NULL;
 
@@ -446,7 +458,7 @@ static void init(int process_parameters)
 	node_counter = 0;
 }
 
-void fifo_terminate()
+void fifo_terminate(void)
 {
 	if (!thread_inited) return;
 
diff --git a/src/libespeak-ng/intonation.c b/src/libespeak-ng/intonation.c
index 60f032d2..8e405677 100644
--- a/src/libespeak-ng/intonation.c
+++ b/src/libespeak-ng/intonation.c
@@ -770,7 +770,6 @@ static void CalcPitches_Tone(Translator *tr)
 {
 	PHONEME_LIST *p;
 	int ix;
-	int count_stressed = 0;
 	int final_stressed = 0;
 
 	int tone_ph;
@@ -791,7 +790,6 @@ static void CalcPitches_Tone(Translator *tr)
 	for (ix = 0; ix < n_phoneme_list; ix++, p++) {
 		if ((p->type == phVOWEL) && (p->stresslevel >= 4)) {
 			final_stressed = ix;
-			count_stressed++;
 		}
 	}
 
diff --git a/src/libespeak-ng/klatt.c b/src/libespeak-ng/klatt.c
index 174b1b7d..dfadcfd9 100644
--- a/src/libespeak-ng/klatt.c
+++ b/src/libespeak-ng/klatt.c
@@ -68,7 +68,7 @@ static klatt_global_t kt_globals;
 
 #define NUMBER_OF_SAMPLES 100
 
-static int scale_wav_tab[] = { 45, 38, 45, 45, 55, 45 }; // scale output from different voicing sources
+static const int scale_wav_tab[] = { 45, 38, 45, 45, 55, 45 }; // scale output from different voicing sources
 
 // For testing, this can be overwritten in KlattInit()
 static const short natural_samples2[256] = {
@@ -547,7 +547,7 @@ static void frame_init(klatt_frame_ptr frame)
    to Kopen.
  */
 
-static double impulsive_source()
+static double impulsive_source(void)
 {
 	static const double doublet[] = { 0.0, 13000000.0, -13000000.0 };
 	static double vwave;
@@ -567,7 +567,7 @@ static double impulsive_source()
    spectral zero around 800 Hz, magic constants a,b reset pitch synchronously.
  */
 
-static double natural_source()
+static double natural_source(void)
 {
 	double lgtemp;
 	static double vwave;
@@ -1068,7 +1068,7 @@ static void SetSynth_Klatt(int length, frame_t *fr1, frame_t *fr2, voice_t *wvoi
 	}
 }
 
-void KlattInit()
+void KlattInit(void)
 {
 
 	static const short formant_hz[10] = { 280, 688, 1064, 2806, 3260, 3700, 6500, 7000, 8000, 280 };
diff --git a/src/libespeak-ng/langopts.c b/src/libespeak-ng/langopts.c
index 247c93ef..31760a08 100644
--- a/src/libespeak-ng/langopts.c
+++ b/src/libespeak-ng/langopts.c
@@ -42,8 +42,6 @@
 static int CheckTranslator(Translator *tr, const MNEM_TAB *keyword_tab, int key);
 static int LookupTune(const char *name);
 
-extern const MNEM_TAB langopts_tab[];
-
 void LoadLanguageOptions(Translator *translator, int key, char *keyValue ) {
 if (CheckTranslator(translator, langopts_tab, key) != 0) {
 				return;
@@ -232,4 +230,4 @@ int CheckTranslator(Translator *tr, const MNEM_TAB *keyword_tab, int key)
 
 	fprintf(stderr, "Cannot set %s: language not set, or is invalid.\n", LookupMnemName(keyword_tab, key));
 	return 1;
-}
\ No newline at end of file
+}
diff --git a/src/libespeak-ng/numbers.c b/src/libespeak-ng/numbers.c
index b2885f59..a71e155f 100644
--- a/src/libespeak-ng/numbers.c
+++ b/src/libespeak-ng/numbers.c
@@ -553,7 +553,7 @@ void LookupLetter(Translator *tr, unsigned int letter, int next_byte, char *ph_b
 
 
 // this list must be in ascending order
-static unsigned short derived_letters[] = {
+static const unsigned short derived_letters[] = {
 	0x00aa, 'a'+L_SUP,
 	0x00b2, '2'+L_SUP,
 	0x00b3, '3'+L_SUP,
@@ -763,14 +763,13 @@ int TranslateRoman(Translator *tr, char *word, char *ph_out, WORD_TAB *wtab)
 	int value;
 	int subtract;
 	int repeat = 0;
-	int n_digits = 0;
 	char *word_start;
 	int num_control = 0;
 	unsigned int flags[2];
 	char ph_roman[30];
 	char number_chars[N_WORD_BYTES];
 
-	static const char *roman_numbers = "ixcmvld";
+	static const char roman_numbers[] = "ixcmvld";
 	static const int roman_values[] = { 1, 10, 100, 1000, 5, 50, 500 };
 
 	acc = 0;
@@ -817,7 +816,6 @@ int TranslateRoman(Translator *tr, char *word, char *ph_out, WORD_TAB *wtab)
 		else
 			acc += prev;
 		prev = value;
-		n_digits++;
 	}
 
 	if (IsDigit09(word[0]))
diff --git a/src/libespeak-ng/phonemelist.c b/src/libespeak-ng/phonemelist.c
index 16346e4f..77361227 100644
--- a/src/libespeak-ng/phonemelist.c
+++ b/src/libespeak-ng/phonemelist.c
@@ -590,4 +590,4 @@ if (ph->type == phVOWEL) {
 			// re-interpret the changed phoneme
 			// But it doesn't obey a second ChangePhoneme()
 			InterpretPhoneme(tr, 0x100, plist3, phdata, worddata);
-}
\ No newline at end of file
+}
diff --git a/src/libespeak-ng/sPlayer.c b/src/libespeak-ng/sPlayer.c
index 075c7ac2..92b28a95 100644
--- a/src/libespeak-ng/sPlayer.c
+++ b/src/libespeak-ng/sPlayer.c
@@ -42,7 +42,7 @@ static void mixWaveFile(WGEN_DATA *wdata, unsigned int maxNumSamples, sample* sa
 	}
 }
 
-static bool isKlattFrameFollowing() {
+static bool isKlattFrameFollowing(void) {
 	// eSpeak implements its command queue with a circular buffer.
 	// Thus to walk it, we start from the head, walking to the tail, which may wrap around to the beginning of the buffer as it is circular.
 	for(int i=(wcmdq_head+1)%N_WCMDQ;i!=wcmdq_tail;i=(i+1)%N_WCMDQ) {
@@ -93,17 +93,17 @@ static void fillSpeechPlayerFrame(WGEN_DATA *wdata, voice_t *wvoice, frame_t * e
 	spFrame->endVoicePitch=spFrame->voicePitch;
 }
 
-void KlattInitSP() {
+void KlattInitSP(void) {
 	speechPlayerHandle=speechPlayer_initialize(22050);
 }
 
-void KlattFiniSP() {
+void KlattFiniSP(void) {
 	if (speechPlayerHandle)
 		speechPlayer_terminate(speechPlayerHandle);
 	speechPlayerHandle = NULL;
 }
 
-void KlattResetSP() {
+void KlattResetSP(void) {
 	KlattFiniSP();
 	KlattInitSP();
 }
diff --git a/src/libespeak-ng/setlengths.c b/src/libespeak-ng/setlengths.c
index 7c1e9381..ffea7384 100644
--- a/src/libespeak-ng/setlengths.c
+++ b/src/libespeak-ng/setlengths.c
@@ -38,7 +38,7 @@
 #include "synthesize.h"
 #include "translate.h"
 
-static void SetSpeedFactors(voice_t *voice, int x, int *speed1, int *speed2, int *speed3);
+static void SetSpeedFactors(voice_t *voice, int x, int speeds[3]);
 static void SetSpeedMods(SPEED_FACTORS *speed, int voiceSpeedF1, int wpm, int x);
 static void SetSpeedMultiplier(int *x, int *wpm);
 
@@ -46,7 +46,7 @@ extern int saved_parameters[];
 
 // convert from words-per-minute to internal speed factor
 // Use this to calibrate speed for wpm 80-450 (espeakRATE_MINIMUM - espeakRATE_MAXIMUM)
-static unsigned char speed_lookup[] = {
+static const unsigned char speed_lookup[] = {
 	255, 255, 255, 255, 255, //  80
 	253, 249, 245, 242, 238, //  85
 	235, 232, 228, 225, 222, //  90
@@ -106,7 +106,7 @@ static unsigned char speed_lookup[] = {
 };
 
 // speed_factor1 adjustments for speeds 350 to 374: pauses
-static unsigned char pause_factor_350[] = {
+static const unsigned char pause_factor_350[] = {
 	22, 22, 22, 22, 22, 22, 22, 21, 21, 21, // 350
 	21, 20, 20, 19, 19, 18, 17, 16, 15, 15, // 360
 	15, 15, 15, 15, 15                      // 370
@@ -114,7 +114,7 @@ static unsigned char pause_factor_350[] = {
 
 // wav_factor adjustments for speeds 350 to 450
 // Use this to calibrate speed for wpm 350-450
-static unsigned char wav_factor_350[] = {
+static const unsigned char wav_factor_350[] = {
 	120, 121, 120, 119, 119, // 350
 	118, 118, 117, 116, 116, // 355
 	115, 114, 113, 112, 112, // 360
@@ -138,9 +138,7 @@ static unsigned char wav_factor_350[] = {
 	 45                      // 450
 };
 
-static int speed1 = 130;
-static int speed2 = 121;
-static int speed3 = 118;
+static int len_speeds[3] = { 130, 121, 118 };
 
 void SetSpeed(int control)
 {
@@ -174,9 +172,9 @@ void SetSpeed(int control)
 		// The eSpeak output will be speeded up by at least x2
 		x = 73;
 		if (control & 1) {
-			speed1 = (x * voice->speedf1)/256;
-			speed2 = (x * voice->speedf2)/256;
-			speed3 = (x * voice->speedf3)/256;
+			len_speeds[0] = (x * voice->speedf1)/256;
+			len_speeds[1] = (x * voice->speedf2)/256;
+			len_speeds[2] = (x * voice->speedf3)/256;
 		}
 		if (control & 2) {
 			double sonic;
@@ -201,7 +199,7 @@ void SetSpeed(int control)
 	SetSpeedMultiplier(&x, &wpm);
 
 	if (control & 1) {
-		SetSpeedFactors(voice, x, &speed1, &speed2, &speed3);
+		SetSpeedFactors(voice, x, len_speeds);
 	}
 
 	if (control & 2) {
@@ -229,16 +227,16 @@ static void SetSpeedMultiplier(int *x, int *wpm) {
 		*x = 6;
 }
 
-static void SetSpeedFactors(voice_t *voice, int x, int *speed1, int *speed2, int *speed3) {
+static void SetSpeedFactors(voice_t *voice, int x, int speeds[3]) {
 	// set speed factors for different syllable positions within a word
 	// these are used in CalcLengths()
-	*speed1 = (x * voice->speedf1)/256;
-	*speed2 = (x * voice->speedf2)/256;
-	*speed3 = (x * voice->speedf3)/256;
+	speeds[0] = (x * voice->speedf1)/256;
+	speeds[1] = (x * voice->speedf2)/256;
+	speeds[2] = (x * voice->speedf3)/256;
 
 	if (x <= 7) {
-		*speed1 = x;
-		*speed2 = *speed3 = x - 1;
+		speeds[0] = x;
+		speeds[1] = speeds[2] = x - 1;
 	}
 }
 
@@ -523,7 +521,7 @@ void CalcLengths(Translator *tr)
 					p->length = prev->length;
 
 					if (p->type == phLIQUID)
-						p->length = speed1;
+						p->length = len_speeds[0];
 
 					if (next->type == phVSTOP)
 						p->length = (p->length * 160)/100;
@@ -615,11 +613,11 @@ void CalcLengths(Translator *tr)
 			}
 
 			if (more_syllables == 0)
-				length_mod *= speed1;
+				length_mod *= len_speeds[0];
 			else if (more_syllables == 1)
-				length_mod *= speed2;
+				length_mod *= len_speeds[1];
 			else
-				length_mod *= speed3;
+				length_mod *= len_speeds[2];
 
 			length_mod = length_mod / 128;
 
@@ -654,9 +652,9 @@ void CalcLengths(Translator *tr)
 				length_mod = length_mod * (256 + (280 - len)/3)/256;
 			}
 
-			if (length_mod > tr->langopts.max_lengthmod*speed1) {
+			if (length_mod > tr->langopts.max_lengthmod*len_speeds[0]) {
 				// limit the vowel length adjustment for some languages
-				length_mod = (tr->langopts.max_lengthmod*speed1);
+				length_mod = (tr->langopts.max_lengthmod*len_speeds[0]);
 			}
 
 			length_mod = length_mod / 128;
diff --git a/src/libespeak-ng/spect.c b/src/libespeak-ng/spect.c
index df1eaf28..02c97216 100644
--- a/src/libespeak-ng/spect.c
+++ b/src/libespeak-ng/spect.c
@@ -36,13 +36,11 @@
 #include "synthesize.h"                // for KLATT_AV, KLATT_Kopen, N_KLATTP2
 #include "voice.h"                     // for N_PEAKS
 
-static int frame_width;
-
-static int default_freq[N_PEAKS] =
+static const int default_freq[N_PEAKS] =
 { 200, 500, 1200, 3000, 3500, 4000, 6900, 7800, 9000 };
-static int default_width[N_PEAKS] =
+static const int default_width[N_PEAKS] =
 { 750, 500, 550, 550, 600, 700, 700, 700, 700 };
-static int default_klt_bw[N_PEAKS] =
+static const int default_klt_bw[N_PEAKS] =
 { 89, 90, 140, 260, 260, 260, 500, 500, 500 };
 
 static double read_double(FILE *stream)
@@ -87,7 +85,7 @@ float polint(float xa[], float ya[], int n, float x)
 	return y;
 }
 
-static SpectFrame *SpectFrameCreate()
+static SpectFrame *SpectFrameCreate(void)
 {
 	int ix;
 	SpectFrame *frame;
@@ -230,7 +228,7 @@ double GetFrameRms(SpectFrame *frame, int seq_amplitude)
 }
 
 #pragma GCC visibility push(default)
-SpectSeq *SpectSeqCreate()
+SpectSeq *SpectSeqCreate(void)
 {
 	SpectSeq *spect = malloc(sizeof(SpectSeq));
 	if (!spect)
@@ -377,9 +375,6 @@ espeak_ng_STATUS LoadSpectSeq(SpectSeq *spect, const char *filename)
 	}
 	spect->max_x = 9000; // disable auto-xscaling
 
-	frame_width = (int)((FRAME_WIDTH*spect->max_x)/MAX_DISPLAY_FREQ);
-	if (frame_width > FRAME_WIDTH) frame_width = FRAME_WIDTH;
-
 	// start times from zero
 	time_offset = spect->frames[0]->time;
 	for (ix = 0; ix < spect->numframes; ix++)
diff --git a/src/libespeak-ng/speech.c b/src/libespeak-ng/speech.c
index 4babf780..c0bbd2ac 100644
--- a/src/libespeak-ng/speech.c
+++ b/src/libespeak-ng/speech.c
@@ -80,7 +80,7 @@ static void *my_user_data = NULL;
 static espeak_ng_OUTPUT_MODE my_mode = ENOUTPUT_MODE_SYNCHRONOUS;
 static int out_samplerate = 0;
 static int voice_samplerate = 22050;
-static int min_buffer_length = 60; // minimum buffer length in ms
+static const int min_buffer_length = 60; // minimum buffer length in ms
 static espeak_ng_STATUS err = ENS_OK;
 
 static t_espeak_callback *synth_callback = NULL;
@@ -428,7 +428,6 @@ static espeak_ng_STATUS Synthesize(unsigned int unique_identifier, const void *t
 	// Fill the buffer with output sound
 	int length;
 	int finished = 0;
-	int count_buffers = 0;
 
 	if ((outbuf == NULL) || (event_list == NULL))
 		return ENS_NOT_INITIALIZED;
@@ -467,7 +466,6 @@ static espeak_ng_STATUS Synthesize(unsigned int unique_identifier, const void *t
 		event_list[event_list_ix].unique_identifier = unique_identifier;
 		event_list[event_list_ix].user_data = my_user_data;
 
-		count_buffers++;
 		if ((my_mode & ENOUTPUT_MODE_SPEAK_AUDIO) == ENOUTPUT_MODE_SPEAK_AUDIO) {
 			finished = create_events((short *)outbuf, length, event_list);
 			if (finished < 0)
@@ -661,7 +659,7 @@ espeak_ng_Synthesize(const void *text, size_t size,
 {
 	(void)size; // unused in non-async modes
 
-	static unsigned int temp_identifier;
+	unsigned int temp_identifier;
 
 	if (unique_identifier == NULL)
 		unique_identifier = &temp_identifier;
@@ -710,7 +708,7 @@ espeak_ng_SynthesizeMark(const void *text,
 {
 	(void)size; // unused in non-async modes
 
-	static unsigned int temp_identifier;
+	unsigned int temp_identifier;
 
 	if (unique_identifier == NULL)
 		unique_identifier = &temp_identifier;
diff --git a/src/libespeak-ng/synthesize.c b/src/libespeak-ng/synthesize.c
index eb50ba9e..7360eaac 100644
--- a/src/libespeak-ng/synthesize.c
+++ b/src/libespeak-ng/synthesize.c
@@ -85,7 +85,7 @@ const char *WordToString(char buf[5], unsigned int word)
 	return buf;
 }
 
-void SynthesizeInit()
+void SynthesizeInit(void)
 {
 	last_pitch_cmd = 0;
 	last_amp_cmd = 0;
@@ -376,7 +376,7 @@ int DoSample3(PHONEME_DATA *phdata, int length_mod, int amp)
 	return len;
 }
 
-static frame_t *AllocFrame()
+static frame_t *AllocFrame(void)
 {
 	// Allocate a temporary spectrum frame for the wavegen queue. Use a pool which is big
 	// enough to use a round-robin without checks.
@@ -1190,9 +1190,9 @@ int Generate(PHONEME_LIST *phoneme_list, int *n_ph, bool resume)
 		if (WcmdqFree() <= free_min)
 			return 1; // wait
 
-			PHONEME_LIST *prev;
-			PHONEME_LIST *next;
-        	PHONEME_LIST *next2;
+		PHONEME_LIST *prev;
+		PHONEME_LIST *next;
+		PHONEME_LIST *next2;
 
 		prev = &phoneme_list[ix-1];
 		next = &phoneme_list[ix+1];
diff --git a/src/libespeak-ng/tr_languages.c b/src/libespeak-ng/tr_languages.c
index c221291d..5ca95055 100644
--- a/src/libespeak-ng/tr_languages.c
+++ b/src/libespeak-ng/tr_languages.c
@@ -1342,7 +1342,7 @@ Translator *SelectTranslator(const char *name)
 	case L('s', 'k'): // Slovak
 	case L('c', 's'): // Czech
 	{
-		static const char *sk_voiced = "bdgjlmnrvwzaeiouy";
+		static const char sk_voiced[] = "bdgjlmnrvwzaeiouy";
 
 		SetupTranslator(tr, stress_lengths_sk, stress_amps_sk);
 		tr->encoding = ESPEAKNG_ENCODING_ISO_8859_2;
diff --git a/src/libespeak-ng/translate.c b/src/libespeak-ng/translate.c
index fe55b83d..6e1860e0 100644
--- a/src/libespeak-ng/translate.c
+++ b/src/libespeak-ng/translate.c
@@ -231,7 +231,7 @@ static int CountSyllables(unsigned char *phonemes)
 	return count;
 }
 
-static void Word_EmbeddedCmd()
+static void Word_EmbeddedCmd(void)
 {
 	// Process embedded commands for emphasis, sayas, and break
 	int embedded_cmd;
diff --git a/src/libespeak-ng/voices.c b/src/libespeak-ng/voices.c
index 98f0cb82..b507902e 100644
--- a/src/libespeak-ng/voices.c
+++ b/src/libespeak-ng/voices.c
@@ -64,7 +64,7 @@ static const MNEM_TAB genders[] = {
 int tone_points[12] = { 600, 170, 1200, 135, 2000, 110, 3000, 110, -1, 0 };
 
 // limit the rate of change for each formant number
-static int formant_rate_22050[9] = { 240, 170, 170, 170, 170, 170, 170, 170, 170 }; // values for 22kHz sample rate
+static const int formant_rate_22050[9] = { 240, 170, 170, 170, 170, 170, 170, 170, 170 }; // values for 22kHz sample rate
 int formant_rate[9]; // values adjusted for actual sample rate
 
 #define DEFAULT_LANGUAGE_PRIORITY  5
@@ -1338,7 +1338,7 @@ ESPEAK_NG_API espeak_ng_STATUS espeak_ng_SetVoiceByProperties(espeak_VOICE *voic
 
 #pragma GCC visibility pop
 
-void FreeVoiceList()
+void FreeVoiceList(void)
 {
 	int ix;
 	for (ix = 0; ix < n_voices_list; ix++) {
@@ -1423,7 +1423,6 @@ static int AddToVoicesList(const char *fname, int len_path_voices, int is_langua
 
 		if (voice_data != NULL)
 			voices_list[n_voices_list++] = voice_data;
-			return 0;
 	}
 	return 0;
 }
diff --git a/src/libespeak-ng/wavegen.c b/src/libespeak-ng/wavegen.c
index 5813b3ad..ba14d707 100644
--- a/src/libespeak-ng/wavegen.c
+++ b/src/libespeak-ng/wavegen.c
@@ -119,7 +119,7 @@ int wcmdq_tail = 0;
 
 // pitch,speed,
 const int embedded_default[N_EMBEDDED_VALUES]    = { 0,     50, espeakRATE_NORMAL, 100, 50,  0,  0, 0, espeakRATE_NORMAL, 0, 0, 0, 0, 0, 0 };
-static int embedded_max[N_EMBEDDED_VALUES] = { 0, 0x7fff, 750, 300, 99, 99, 99, 0, 750, 0, 0, 0, 0, 4, 0 };
+static const int embedded_max[N_EMBEDDED_VALUES] = { 0, 0x7fff, 750, 300, 99, 99, 99, 0, 750, 0, 0, 0, 0, 4, 0 };
 
 #if USE_LIBSONIC
 static sonicStream sonicSpeedupStream = NULL;
@@ -130,7 +130,7 @@ static double sonicSpeed = 1.0;
 // 2nd index=modulation_type
 // value: bits 0-3  amplitude (16ths), bits 4-7 every n cycles
 #define N_ROUGHNESS 8
-static unsigned char modulation_tab[N_ROUGHNESS][8] = {
+static const unsigned char modulation_tab[N_ROUGHNESS][8] = {
 	{ 0, 0x00, 0x00, 0x00, 0, 0x46, 0xf2, 0x29 },
 	{ 0, 0x2f, 0x00, 0x2f, 0, 0x45, 0xf2, 0x29 },
 	{ 0, 0x2f, 0x00, 0x2e, 0, 0x45, 0xf2, 0x28 },
@@ -234,7 +234,7 @@ static const unsigned char pitch_adjust_tab[MAX_PITCH_VALUE+1] = {
 	242, 246, 249, 252, 254, 255
 };
 
-void WcmdqStop()
+void WcmdqStop(void)
 {
 	wcmdq_head = 0;
 	wcmdq_tail = 0;
@@ -252,7 +252,7 @@ void WcmdqStop()
 #endif
 }
 
-int WcmdqFree()
+int WcmdqFree(void)
 {
 	int i;
 	i = wcmdq_head - wcmdq_tail;
@@ -260,18 +260,18 @@ int WcmdqFree()
 	return i;
 }
 
-int WcmdqUsed()
+int WcmdqUsed(void)
 {
 	return N_WCMDQ - WcmdqFree();
 }
 
-void WcmdqInc()
+void WcmdqInc(void)
 {
 	wcmdq_tail++;
 	if (wcmdq_tail >= N_WCMDQ) wcmdq_tail = 0;
 }
 
-static void WcmdqIncHead()
+static void WcmdqIncHead(void)
 {
 	MAKE_MEM_UNDEFINED(&wcmdq[wcmdq_head], sizeof(wcmdq[wcmdq_head]));
 	wcmdq_head++;
@@ -534,7 +534,7 @@ int PeaksToHarmspect(wavegen_peaks_t *peaks, int pitch, int *htab, int control)
 	return hmax; // highest harmonic number
 }
 
-static void AdvanceParameters()
+static void AdvanceParameters(void)
 {
 	// Called every 64 samples to increment the formant freq, height, and widths
 	if (wvoice == NULL)
@@ -643,7 +643,7 @@ void InitBreath(void)
 		setresonator(&rbreath[ix], 2000, 200, 1);
 }
 
-static void SetBreath()
+static void SetBreath(void)
 {
 	int pk;
 
@@ -1001,7 +1001,7 @@ static int SetWithRange0(int value, int max)
 	return value;
 }
 
-static void SetPitchFormants()
+static void SetPitchFormants(void)
 {
 	if (wvoice == NULL)
 		return;
@@ -1253,7 +1253,7 @@ void Write4Bytes(FILE *f, int value)
 	}
 }
 
-static int WavegenFill2()
+static int WavegenFill2(void)
 {
 	// Pick up next wavegen commands from the queue
 	// return: 0  output buffer has been filled