diff --git a/Makefile.am b/Makefile.am
index 61b33a52..52df9575 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -245,11 +245,11 @@ tests_readclause_test_CFLAGS  = -Isrc/libespeak-ng ${AM_CFLAGS}
 tests_readclause_test_LDADD   = src/libespeak-ng-test.la
 tests_readclause_test_SOURCES = tests/readclause.c
 
-noinst_bin_PROGRAMS += tests/voices.test
+noinst_bin_PROGRAMS += tests/api.test
 
-tests_voices_test_LDADD   = src/libespeak-ng-test.la
-tests_voices_test_CFLAGS  = -Isrc/libespeak-ng ${AM_CFLAGS}
-tests_voices_test_SOURCES = tests/voices.c
+tests_api_test_CFLAGS  = -Isrc/libespeak-ng ${AM_CFLAGS}
+tests_api_test_LDADD   = src/libespeak-ng-test.la
+tests_api_test_SOURCES = tests/api.c
 
 %.check: %.test
 	@echo "  TEST      $<"
@@ -258,7 +258,7 @@ tests_voices_test_SOURCES = tests/voices.c
 check:	tests/encoding.check \
 	tests/tokenizer.check \
 	tests/readclause.check \
-	tests/voices.check \
+	tests/api.check \
 	tests/languages.check
 
 ##### phoneme data:
diff --git a/src/libespeak-ng/speech.c b/src/libespeak-ng/speech.c
index 368520db..bd8cd294 100644
--- a/src/libespeak-ng/speech.c
+++ b/src/libespeak-ng/speech.c
@@ -58,6 +58,7 @@
 #include "event.h"
 
 unsigned char *outbuf = NULL;
+int outbuf_size = 0;
 
 espeak_EVENT *event_list = NULL;
 int event_list_ix = 0;
@@ -252,7 +253,8 @@ ESPEAK_NG_API espeak_ng_STATUS espeak_ng_InitializeOutput(espeak_ng_OUTPUT_MODE
 	out_samplerate = 0;
 
 #ifdef HAVE_PCAUDIOLIB_AUDIO_H
-	my_audio = create_audio_device_object(device, "eSpeak", "Text-to-Speech");
+	if (my_audio == NULL)
+		my_audio = create_audio_device_object(device, "eSpeak", "Text-to-Speech");
 #endif
 
 	// buffer_length is in mS, allocate 2 bytes per sample
@@ -396,13 +398,16 @@ static espeak_ng_STATUS Synthesize(unsigned int unique_identifier, const void *t
 
 	count_samples = 0;
 
-	if (translator == NULL)
-		espeak_SetVoiceByName("default");
+	espeak_ng_STATUS status;
+	if (translator == NULL) {
+		status = espeak_SetVoiceByName("en");
+		if (status != ENS_OK)
+			return status;
+	}
 
 	if (p_decoder == NULL)
 		p_decoder = create_text_decoder();
 
-	espeak_ng_STATUS status;
 	status = text_decoder_decode_string_multibyte(p_decoder, text, translator->encoding, flags);
 	if (status != ENS_OK)
 		return status;
@@ -886,6 +891,7 @@ ESPEAK_NG_API espeak_ng_STATUS espeak_ng_Terminate(void)
 #ifdef HAVE_PCAUDIOLIB_AUDIO_H
 		audio_object_close(my_audio);
 		audio_object_destroy(my_audio);
+		my_audio = NULL;
 #endif
 		out_samplerate = 0;
 	}
@@ -896,6 +902,12 @@ ESPEAK_NG_API espeak_ng_STATUS espeak_ng_Terminate(void)
 	outbuf = NULL;
 	FreePhData();
 	FreeVoiceList();
+	translator = NULL;
+
+	if (p_decoder != NULL) {
+		destroy_text_decoder(p_decoder);
+		p_decoder = NULL;
+	}
 
 	return ENS_OK;
 }
diff --git a/src/libespeak-ng/synthesize.h b/src/libespeak-ng/synthesize.h
index a83784c4..a2c52ea0 100644
--- a/src/libespeak-ng/synthesize.h
+++ b/src/libespeak-ng/synthesize.h
@@ -512,7 +512,6 @@ extern int formant_rate[];         // max rate of change of each formant
 extern SPEED_FACTORS speed;
 
 extern long count_samples;
-extern int outbuf_size;
 extern unsigned char *out_ptr;
 extern unsigned char *out_start;
 extern unsigned char *out_end;
diff --git a/src/libespeak-ng/wavegen.c b/src/libespeak-ng/wavegen.c
index ee355625..dd656f9c 100644
--- a/src/libespeak-ng/wavegen.c
+++ b/src/libespeak-ng/wavegen.c
@@ -107,7 +107,6 @@ static double two_pi_t;
 unsigned char *out_ptr;
 unsigned char *out_start;
 unsigned char *out_end;
-int outbuf_size = 0;
 
 // the queue of operations passed to wavegen from sythesize
 intptr_t wcmdq[N_WCMDQ][4];
diff --git a/tests/api.c b/tests/api.c
new file mode 100644
index 00000000..b7cdacce
--- /dev/null
+++ b/tests/api.c
@@ -0,0 +1,145 @@
+/*
+ * Copyright (C) 2017 Reece H. Dunn
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write see:
+ *             <http://www.gnu.org/licenses/>.
+ */
+
+#include "config.h"
+
+#include <assert.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include <espeak-ng/espeak_ng.h>
+#include <espeak-ng/speak_lib.h>
+#include <espeak-ng/encoding.h>
+
+#include "speech.h"
+#include "phoneme.h"
+#include "synthesize.h"
+#include "translate.h"
+
+void
+test_espeak_terminate_without_initialize()
+{
+	printf("testing espeak_Terminate without espeak_Initialize\n");
+
+	assert(event_list == NULL);
+	assert(translator == NULL);
+	assert(p_decoder == NULL);
+
+	assert(espeak_Terminate() == EE_OK);
+	assert(event_list == NULL);
+	assert(translator == NULL);
+	assert(p_decoder == NULL);
+}
+
+void
+test_espeak_initialize()
+{
+	printf("testing espeak_Initialize\n");
+
+	assert(event_list == NULL);
+	assert(translator == NULL);
+	assert(p_decoder == NULL);
+
+	assert(espeak_Initialize(AUDIO_OUTPUT_PLAYBACK, 0, NULL, 0) == 22050);
+	assert(event_list != NULL);
+	assert(translator == NULL);
+	assert(p_decoder == NULL);
+
+	assert(espeak_Terminate() == EE_OK);
+	assert(event_list == NULL);
+	assert(translator == NULL);
+	assert(p_decoder == NULL);
+}
+
+void
+test_espeak_synth()
+{
+	printf("testing espeak_Synth\n");
+
+	assert(event_list == NULL);
+	assert(translator == NULL);
+	assert(p_decoder == NULL);
+
+	assert(espeak_Initialize(AUDIO_OUTPUT_RETRIEVAL, 0, NULL, 0) == 22050);
+	assert(event_list != NULL);
+	assert(translator == NULL);
+	assert(p_decoder == NULL);
+
+	const char *test = "One two three.";
+	assert(espeak_Synth(test, strlen(test)+1, 0, POS_CHARACTER, 0, espeakCHARS_AUTO, NULL, NULL) == EE_OK);
+	assert(translator != NULL);
+	assert(p_decoder != NULL);
+
+	assert(espeak_Synchronize() == EE_OK);
+	assert(translator != NULL);
+	assert(p_decoder != NULL);
+
+	assert(espeak_Terminate() == EE_OK);
+	assert(event_list == NULL);
+	assert(translator == NULL);
+	assert(p_decoder == NULL);
+}
+
+void
+test_espeak_synth_no_voices(const char *path)
+{
+	printf("testing espeak_Synth in path with no voices\n");
+
+	assert(event_list == NULL);
+	assert(translator == NULL);
+	assert(p_decoder == NULL);
+
+	assert(espeak_Initialize(AUDIO_OUTPUT_RETRIEVAL, 0, path, espeakINITIALIZE_DONT_EXIT) == 22050);
+	assert(event_list != NULL);
+	assert(translator == NULL);
+	assert(p_decoder == NULL);
+
+	const char *test = "One two three.";
+	assert(espeak_Synth(test, strlen(test)+1, 0, POS_CHARACTER, 0, espeakCHARS_AUTO, NULL, NULL) == EE_INTERNAL_ERROR);
+	assert(translator == NULL);
+	assert(p_decoder == NULL);
+
+	assert(espeak_Synchronize() == EE_OK);
+	assert(translator == NULL);
+	assert(p_decoder == NULL);
+
+	assert(espeak_Terminate() == EE_OK);
+	assert(event_list == NULL);
+	assert(translator == NULL);
+	assert(p_decoder == NULL);
+}
+
+int
+main(int argc, char **argv)
+{
+	char *progdir = strdup(argv[0]);
+	char *dir = strrchr(progdir, '/');
+	if (dir != NULL) *dir = 0;
+
+	test_espeak_terminate_without_initialize();
+	test_espeak_initialize();
+
+	test_espeak_synth();
+	test_espeak_synth(); // Check that this does not crash when run a second time.
+	test_espeak_synth_no_voices(progdir);
+	test_espeak_synth();
+
+	free(progdir);
+
+	return EXIT_SUCCESS;
+}
diff --git a/tests/readclause.c b/tests/readclause.c
index ce3ba148..90dbd72f 100644
--- a/tests/readclause.c
+++ b/tests/readclause.c
@@ -34,10 +34,32 @@
 #include "synthesize.h"
 #include "translate.h"
 
-void
-test_latin_common()
+// Arguments to ReadClause. Declared here to avoid duplicating them across the
+// different test functions.
+static char source[N_TR_SOURCE+40]; // extra space for embedded command & voice change info at end
+static short charix[N_TR_SOURCE+4];
+static int charix_top = 0;
+static int tone2;
+static char voice_change_name[40];
+static int terminator;
+
+static espeak_ng_STATUS
+set_text(const char *text, const char *voicename)
 {
-	printf("testing Latin/Common (Latn/Zyyy) script classification\n");
+	espeak_ng_STATUS status = espeak_ng_SetVoiceByName(voicename);
+	if (status != ENS_OK)
+		return status;
+
+	if (p_decoder == NULL)
+		p_decoder = create_text_decoder();
+
+	return text_decoder_decode_string(p_decoder, text, -1, ESPEAKNG_ENCODING_UTF_8);
+}
+
+void
+test_latin()
+{
+	printf("testing Latin (Latn)\n");
 
 	assert(clause_type_from_codepoint('a') == CLAUSE_NONE);
 	assert(clause_type_from_codepoint('.') == CLAUSE_PERIOD);
@@ -58,7 +80,7 @@ test_latin_common()
 void
 test_greek()
 {
-	printf("testing Greek (Grek) script classification\n");
+	printf("testing Greek (Grek)\n");
 
 	assert(clause_type_from_codepoint(0x037E) == CLAUSE_QUESTION);
 	assert(clause_type_from_codepoint(0x0387) == CLAUSE_SEMICOLON);
@@ -67,7 +89,7 @@ test_greek()
 void
 test_armenian()
 {
-	printf("testing Armenian (Armn) script classification\n");
+	printf("testing Armenian (Armn)\n");
 
 	assert(clause_type_from_codepoint(0x055B) == (CLAUSE_EXCLAMATION | CLAUSE_PUNCTUATION_IN_WORD));
 	assert(clause_type_from_codepoint(0x055C) == (CLAUSE_EXCLAMATION | CLAUSE_PUNCTUATION_IN_WORD));
@@ -79,7 +101,7 @@ test_armenian()
 void
 test_arabic()
 {
-	printf("testing Arabic (Arab) script classification\n");
+	printf("testing Arabic (Arab)\n");
 
 	assert(clause_type_from_codepoint(0x060C) == CLAUSE_COMMA);
 	assert(clause_type_from_codepoint(0x061B) == CLAUSE_SEMICOLON);
@@ -90,7 +112,7 @@ test_arabic()
 void
 test_devanagari()
 {
-	printf("testing Devanagari (Deva) script classification\n");
+	printf("testing Devanagari (Deva)\n");
 
 	assert(clause_type_from_codepoint(0x0964) == (CLAUSE_PERIOD | CLAUSE_OPTIONAL_SPACE_AFTER));
 }
@@ -98,7 +120,7 @@ test_devanagari()
 void
 test_tibetan()
 {
-	printf("testing Tibetan (Tibt) script classification\n");
+	printf("testing Tibetan (Tibt)\n");
 
 	assert(clause_type_from_codepoint(0x0F0D) == (CLAUSE_PERIOD | CLAUSE_OPTIONAL_SPACE_AFTER));
 	assert(clause_type_from_codepoint(0x0F0E) == CLAUSE_PARAGRAPH);
@@ -107,7 +129,7 @@ test_tibetan()
 void
 test_sinhala()
 {
-	printf("testing Sinhala (Sinh) script classification\n");
+	printf("testing Sinhala (Sinh)\n");
 
 	assert(clause_type_from_codepoint(0x0DF4) == (CLAUSE_PERIOD | CLAUSE_OPTIONAL_SPACE_AFTER));
 }
@@ -115,7 +137,7 @@ test_sinhala()
 void
 test_georgian()
 {
-	printf("testing Georgian (Geor) script classification\n");
+	printf("testing Georgian (Geor)\n");
 
 	assert(clause_type_from_codepoint(0x10FB) == CLAUSE_PARAGRAPH);
 }
@@ -123,7 +145,7 @@ test_georgian()
 void
 test_ethiopic()
 {
-	printf("testing Ethiopic (Ethi) script classification\n");
+	printf("testing Ethiopic (Ethi)\n");
 
 	assert(clause_type_from_codepoint(0x1362) == CLAUSE_PERIOD);
 	assert(clause_type_from_codepoint(0x1363) == CLAUSE_COMMA);
@@ -137,7 +159,7 @@ test_ethiopic()
 void
 test_ideographic()
 {
-	printf("testing Ideographic (Hani) script classification\n");
+	printf("testing Ideographic (Hani)\n");
 
 	assert(clause_type_from_codepoint(0x3001) == (CLAUSE_COMMA | CLAUSE_OPTIONAL_SPACE_AFTER));
 	assert(clause_type_from_codepoint(0x3002) == (CLAUSE_PERIOD | CLAUSE_OPTIONAL_SPACE_AFTER));
@@ -146,7 +168,7 @@ test_ideographic()
 void
 test_fullwidth()
 {
-	printf("testing Full Width/Common (Zyyy) script classification\n");
+	printf("testing Full Width\n");
 
 	assert(clause_type_from_codepoint(0xFF01) == (CLAUSE_EXCLAMATION | CLAUSE_OPTIONAL_SPACE_AFTER));
 	assert(clause_type_from_codepoint(0xFF0C) == (CLAUSE_COMMA | CLAUSE_OPTIONAL_SPACE_AFTER));
@@ -156,10 +178,48 @@ test_fullwidth()
 	assert(clause_type_from_codepoint(0xFF1F) == (CLAUSE_QUESTION | CLAUSE_OPTIONAL_SPACE_AFTER));
 }
 
+void
+test_uts51_emoji_character()
+{
+	printf("testing Emoji ... UTS-51 ED-3. emoji character\n");
+
+	short retix[] = {
+		0, -1, -1,
+		2, -1, -1,
+		3, -1, -1,
+		4, -1, -1, -1,
+		5, -1, -1, -1,
+		6,
+		0 };
+
+	assert(set_text(
+		"\xE2\x86\x94"      // [2194]  left right arrow
+		"\xE2\x86\x95"      // [2195]  up down arrow
+		"\xE2\x9B\x94"      // [26D5]  no entry
+		"\xF0\x9F\x90\x8B"  // [1F40B] whale
+		"\xF0\x9F\x90\xAC", // [1F42C] dolphin
+		"en") == ENS_OK);
+
+	assert(ReadClause(translator, source, charix, &charix_top, N_TR_SOURCE, &tone2, voice_change_name) == CLAUSE_EOF);
+	assert(!strcmp(source,
+		"\xE2\x86\x94"     // [2194]  left right arrow
+		"\xE2\x86\x95"     // [2195]  up down arrow
+		"\xE2\x9B\x94"     // [26D5]  no entry
+		"\xF0\x9F\x90\x8B" // [1F40B] whale
+		"\xF0\x9F\x90\xAC" // [1F42C] dolphin
+		" "));
+	assert(charix_top == (sizeof(retix)/sizeof(retix[0])) - 2);
+	assert(!memcmp(charix, retix, sizeof(retix)));
+	assert(tone2 == 0);
+	assert(voice_change_name[0] == 0);
+}
+
 int
 main(int argc, char **argv)
 {
-	test_latin_common();
+	assert(espeak_Initialize(AUDIO_OUTPUT_SYNCHRONOUS, 0, NULL, espeakINITIALIZE_DONT_EXIT) == 22050);
+
+	test_latin();
 	test_greek();
 	test_armenian();
 	test_arabic();
@@ -171,5 +231,12 @@ main(int argc, char **argv)
 	test_ideographic();
 	test_fullwidth();
 
+	test_uts51_emoji_character();
+
+	assert(espeak_Terminate() == EE_OK);
+
 	return EXIT_SUCCESS;
 }
+
+// References:
+//    [UTS-51]     Unicode Emoji (http://www.unicode.org/reports/tr51/tr51-12.html) 5.0-12. 2017-05-18
diff --git a/tests/voices.c b/tests/voices.c
deleted file mode 100644
index d5775a74..00000000
--- a/tests/voices.c
+++ /dev/null
@@ -1,53 +0,0 @@
-/*
- * Copyright (C) 2017 Reece H. Dunn
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 3 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write see:
- *             <http://www.gnu.org/licenses/>.
- */
-
-#include "config.h"
-
-#include <assert.h>
-#include <stdint.h>
-#include <stdlib.h>
-#include <stdio.h>
-
-#include <espeak-ng/espeak_ng.h>
-#include <espeak-ng/speak_lib.h>
-
-void
-test_selection_by_name()
-{
-	printf("testing selection of voice by name\n");
-
-	assert(espeak_SetVoiceByName("de") == EE_OK);
-
-	assert(espeak_SetVoiceByName("und") == EE_NOT_FOUND);
-
-	assert(espeak_ng_SetVoiceByName("de") == ENS_OK);
-
-	assert(espeak_ng_SetVoiceByName("und") == ENS_VOICE_NOT_FOUND);
-}
-
-int
-main(int argc, char **argv)
-{
-	assert(espeak_Initialize(AUDIO_OUTPUT_SYNCHRONOUS, 0, NULL, espeakINITIALIZE_DONT_EXIT) == 22050);
-
-	test_selection_by_name();
-
-	assert(espeak_Terminate() == EE_OK);
-
-	return EXIT_SUCCESS;
-}