diff --git a/docs/voices.md b/docs/voices.md
index 716a0150..0772e852 100644
--- a/docs/voices.md
+++ b/docs/voices.md
@@ -30,7 +30,7 @@
   - [stressAmp](#stressamp)
   - [intonation](#intonation)
   - [dictmin](#dictmin)
-
+  - [letterVowel](#letterVowel)
 ----------
 
 A Voice file specifies a language (and possibly a language variant or
@@ -425,3 +425,9 @@ Used for some languages to detect if additional language data is
 installed. If the size of the compiled dictionary data for the language
 (the file `espeak-ng-data/*_dict`) is less than this size then a
 warning is given.
+
+### letterVowel
+
+	letterVowel <letter>
+
+Used for some languages to handle a certain letter as a vowel instead of consonant.
diff --git a/espeak-ng-data/lang/art/jbo b/espeak-ng-data/lang/art/jbo
index 9cf2f309..70164f70 100644
--- a/espeak-ng-data/lang/art/jbo
+++ b/espeak-ng-data/lang/art/jbo
@@ -2,3 +2,4 @@ name Lojban
 language jbo
 
 speed 80   // speed adjustment, percentage
+letterVowel y
diff --git a/espeak-ng-data/lang/cel/cy b/espeak-ng-data/lang/cel/cy
index 6d021329..dc51c1e8 100644
--- a/espeak-ng-data/lang/cel/cy
+++ b/espeak-ng-data/lang/cel/cy
@@ -2,3 +2,5 @@ name Welsh
 language cy
 
 intonation 4
+letterVowel w
+letterVowel y
diff --git a/espeak-ng-data/lang/gmq/da b/espeak-ng-data/lang/gmq/da
index 58f02f15..fd77dbdb 100644
--- a/espeak-ng-data/lang/gmq/da
+++ b/espeak-ng-data/lang/gmq/da
@@ -2,3 +2,4 @@ name Danish
 language da
 
 tunes s2 c2 q2 e2
+letterVowel y
diff --git a/espeak-ng-data/lang/gmq/is b/espeak-ng-data/lang/gmq/is
index 04bf5ad3..938c9ec0 100644
--- a/espeak-ng-data/lang/gmq/is
+++ b/espeak-ng-data/lang/gmq/is
@@ -1,2 +1,3 @@
 name Icelandic
 language is
+letterVowel y
diff --git a/espeak-ng-data/lang/gmq/nb b/espeak-ng-data/lang/gmq/nb
index c29117f5..d2c78ac8 100644
--- a/espeak-ng-data/lang/gmq/nb
+++ b/espeak-ng-data/lang/gmq/nb
@@ -5,3 +5,4 @@ phonemes no
 dictionary no
 
 intonation 4
+letterVowel y
diff --git a/espeak-ng-data/lang/gmq/sv b/espeak-ng-data/lang/gmq/sv
index bb2d0299..1724c2e4 100644
--- a/espeak-ng-data/lang/gmq/sv
+++ b/espeak-ng-data/lang/gmq/sv
@@ -1,2 +1,3 @@
 name Swedish
 language sv
+letterVowel y
diff --git a/espeak-ng-data/lang/gmw/af b/espeak-ng-data/lang/gmw/af
index 64fc96f5..fb2ce120 100644
--- a/espeak-ng-data/lang/gmw/af
+++ b/espeak-ng-data/lang/gmw/af
@@ -6,3 +6,4 @@ status mature
 
 roughness 0
 pitch 63 120
+letterVowel y
diff --git a/espeak-ng-data/lang/gmw/de b/espeak-ng-data/lang/gmw/de
index 470e5afd..31a1dc23 100644
--- a/espeak-ng-data/lang/gmw/de
+++ b/espeak-ng-data/lang/gmw/de
@@ -1,2 +1,4 @@
 name German
 language de
+
+letterVowel y
diff --git a/espeak-ng-data/lang/gmw/nl b/espeak-ng-data/lang/gmw/nl
index a212fbef..b0711137 100644
--- a/espeak-ng-data/lang/gmw/nl
+++ b/espeak-ng-data/lang/gmw/nl
@@ -1,2 +1,3 @@
 name Dutch
 language nl
+letterVowel y
diff --git a/espeak-ng-data/lang/ine/sq b/espeak-ng-data/lang/ine/sq
index 9ace3576..3cd293d5 100644
--- a/espeak-ng-data/lang/ine/sq
+++ b/espeak-ng-data/lang/ine/sq
@@ -1,5 +1,6 @@
 name Albanian
 language sq
+letterVowel y
 
 // add this line to remove 'ë' at the end of words
 // replace 00  @/  NULL
diff --git a/espeak-ng-data/lang/roa/fr b/espeak-ng-data/lang/roa/fr
index 9e0b9440..e26c916d 100644
--- a/espeak-ng-data/lang/roa/fr
+++ b/espeak-ng-data/lang/roa/fr
@@ -4,3 +4,4 @@ language fr
 
 dictrules 1
 tunes s3 c3 q3 e3
+letterVowel y
diff --git a/espeak-ng-data/lang/roa/fr-BE b/espeak-ng-data/lang/roa/fr-BE
index 1a0311f9..9103eb56 100644
--- a/espeak-ng-data/lang/roa/fr-BE
+++ b/espeak-ng-data/lang/roa/fr-BE
@@ -4,5 +4,5 @@ language fr 8
 
 dictrules 2
 tunes s3 c3 q3 e3
-
+letterVowel y
 
diff --git a/espeak-ng-data/lang/roa/fr-CH b/espeak-ng-data/lang/roa/fr-CH
index 2e45fbd1..4a31800a 100644
--- a/espeak-ng-data/lang/roa/fr-CH
+++ b/espeak-ng-data/lang/roa/fr-CH
@@ -4,3 +4,4 @@ language fr 8
 
 dictrules 3
 tunes s3 c3 q3 e3
+letterVowel y
diff --git a/espeak-ng-data/lang/roa/it b/espeak-ng-data/lang/roa/it
index ad7bb50e..092aebe6 100644
--- a/espeak-ng-data/lang/roa/it
+++ b/espeak-ng-data/lang/roa/it
@@ -5,3 +5,4 @@ maintainer Christian Leo M <llajta2012@gmail.com>
 status mature
 
 tunes s4 c4 q4 e4
+letterVowel y
diff --git a/espeak-ng-data/lang/roa/pt b/espeak-ng-data/lang/roa/pt
index 5041b511..0a2f181c 100644
--- a/espeak-ng-data/lang/roa/pt
+++ b/espeak-ng-data/lang/roa/pt
@@ -5,3 +5,4 @@ phonemes pt-pt
 
 dictrules 1
 intonation 2
+letterVowel y
diff --git a/espeak-ng-data/lang/urj/fi b/espeak-ng-data/lang/urj/fi
index ef14b147..0a944a77 100644
--- a/espeak-ng-data/lang/urj/fi
+++ b/espeak-ng-data/lang/urj/fi
@@ -1,2 +1,3 @@
 name Finnish
 language fi
+letterVowel y
diff --git a/espeak-ng-data/lang/urj/hu b/espeak-ng-data/lang/urj/hu
index 5ece4b1b..adb35805 100644
--- a/espeak-ng-data/lang/urj/hu
+++ b/espeak-ng-data/lang/urj/hu
@@ -2,5 +2,5 @@ name Hungarian
 language hu
 option bracket 0 0
 pitch 81 117
-
+letterVowel y
 
diff --git a/espeak-ng-data/lang/zls/bg b/espeak-ng-data/lang/zls/bg
index 870c0424..9efaa699 100644
--- a/espeak-ng-data/lang/zls/bg
+++ b/espeak-ng-data/lang/zls/bg
@@ -3,3 +3,5 @@ language bg
 
 stressAmp 13 12 17 17 20 22 22 21 
 stressLength 180 170  200 200  200 200  210 220
+letterVowel 0x2a
+
diff --git a/espeak-ng-data/lang/zls/bs b/espeak-ng-data/lang/zls/bs
index 01fd1746..4dcaabcc 100644
--- a/espeak-ng-data/lang/zls/bs
+++ b/espeak-ng-data/lang/zls/bs
@@ -12,3 +12,5 @@ formant 5  97 102 100
 
 stressAdd 10 10 0 0 0 0 -30 -30
 dictrules 3 4
+letterVowel y
+letterVowel r
diff --git a/espeak-ng-data/lang/zls/hr b/espeak-ng-data/lang/zls/hr
index d1cae3a3..3d6214a7 100644
--- a/espeak-ng-data/lang/zls/hr
+++ b/espeak-ng-data/lang/zls/hr
@@ -13,3 +13,5 @@ formant 5  97 102 100
 
 stressAdd 10 10 0 0 0 0 -30 -30
 dictrules 1
+letterVowel y
+letterVowel r
diff --git a/espeak-ng-data/lang/zls/sr b/espeak-ng-data/lang/zls/sr
index 81e33907..b9deeea3 100644
--- a/espeak-ng-data/lang/zls/sr
+++ b/espeak-ng-data/lang/zls/sr
@@ -11,3 +11,6 @@ formant 5  97 102 100
 
 stressAdd 10 10 0 0 0 0 -30 -30
 dictrules 2 4
+
+letterVowel y
+letterVowel r
diff --git a/espeak-ng-data/lang/zlw/cs b/espeak-ng-data/lang/zlw/cs
index 5c3bf2ac..6e2413a4 100644
--- a/espeak-ng-data/lang/zlw/cs
+++ b/espeak-ng-data/lang/zlw/cs
@@ -1,2 +1,4 @@
 name Czech
 language cs
+letterVowel y
+letterVowel r
diff --git a/espeak-ng-data/lang/zlw/pl b/espeak-ng-data/lang/zlw/pl
index b85f56be..09a29334 100644
--- a/espeak-ng-data/lang/zlw/pl
+++ b/espeak-ng-data/lang/zlw/pl
@@ -2,3 +2,4 @@ name Polish
 language pl
 
 intonation 2
+letterVowel y
diff --git a/espeak-ng-data/lang/zlw/sk b/espeak-ng-data/lang/zlw/sk
index e849e61b..2db37b03 100644
--- a/espeak-ng-data/lang/zlw/sk
+++ b/espeak-ng-data/lang/zlw/sk
@@ -1,2 +1,4 @@
 name Slovak
 language sk
+letterVowel y
+letterVowel r
diff --git a/src/libespeak-ng/tr_languages.c b/src/libespeak-ng/tr_languages.c
index bc3a09cc..029389b3 100644
--- a/src/libespeak-ng/tr_languages.c
+++ b/src/libespeak-ng/tr_languages.c
@@ -121,11 +121,6 @@ ALPHABET *AlphabetFromChar(int c)
 
 static void Translator_Russian(Translator *tr);
 
-static void SetLetterVowel(Translator *tr, int c)
-{
-	tr->letter_bits[c] = (tr->letter_bits[c] & 0x40) | 0x81; // keep value for group 6 (front vowels e,i,y)
-}
-
 static void ResetLetterBits(Translator *tr, int groups)
 {
 	// Clear all the specified groups
@@ -483,7 +478,6 @@ Translator *SelectTranslator(const char *name)
 		tr->langopts.vowel_pause = 0x30;
 		tr->langopts.param[LOPT_DIERESES] = 1;
 		tr->langopts.param[LOPT_PREFIXES] = 1;
-		SetLetterVowel(tr, 'y'); // add 'y' to vowels
 
 		tr->langopts.numbers = NUM_SWAP_TENS | NUM_HUNDRED_AND | NUM_SINGLE_AND | NUM_ROMAN | NUM_1900;
 		tr->langopts.accents = 1;
@@ -512,7 +506,6 @@ Translator *SelectTranslator(const char *name)
 	case L('b', 'g'): // Bulgarian
 	{
 		SetCyrillicLetters(tr);
-		SetLetterVowel(tr, 0x2a);
 		tr->encoding = ESPEAKNG_ENCODING_ISO_8859_5;
 		tr->langopts.param[LOPT_UNPRONOUNCABLE] = 0x432; // [v]  don't count this character at start of word
 		tr->langopts.param[LOPT_REGRESSIVE_VOICING] = 0x107; // devoice at end of word, and change voicing to match a following consonant (except v)
@@ -581,8 +574,6 @@ Translator *SelectTranslator(const char *name)
 
 		tr->langopts.numbers = NUM_OMIT_1_HUNDRED;
 
-		SetLetterVowel(tr, 'w'); // add letter to vowels and remove from consonants
-		SetLetterVowel(tr, 'y');
 	}
 		break;
 	case L('d', 'a'): // Danish
@@ -592,7 +583,6 @@ Translator *SelectTranslator(const char *name)
 
 		tr->langopts.stress_rule = STRESSPOSN_1L;
 		tr->langopts.param[LOPT_PREFIXES] = 1;
-		SetLetterVowel(tr, 'y');
 		tr->langopts.numbers = NUM_DECIMAL_COMMA | NUM_SWAP_TENS | NUM_HUNDRED_AND | NUM_OMIT_1_HUNDRED | NUM_ORDINAL_DOT | NUM_1900 | NUM_ROMAN | NUM_ROMAN_CAPITALS | NUM_ROMAN_ORDINAL;
 	}
 		break;
@@ -609,7 +599,6 @@ Translator *SelectTranslator(const char *name)
 		tr->langopts.param[LOPT_LONG_VOWEL_THRESHOLD] = 175/2;
 
 		tr->langopts.numbers = NUM_DECIMAL_COMMA | NUM_SWAP_TENS | NUM_ALLOW_SPACE | NUM_ORDINAL_DOT | NUM_ROMAN;
-		SetLetterVowel(tr, 'y');
 		tr->langopts.param[LOPT_UNPRONOUNCABLE] = 2; // use de_rules for unpronouncable rules
 	}
 		break;
@@ -801,7 +790,6 @@ Translator *SelectTranslator(const char *name)
 		tr->langopts.long_stop = 130;
 
 		tr->langopts.numbers = NUM_DECIMAL_COMMA + NUM_ALLOW_SPACE;
-		SetLetterVowel(tr, 'y');
 		tr->langopts.spelling_stress = 1;
 		tr->langopts.intonation_group = 3; // less intonation, don't raise pitch at comma
 	}
@@ -816,7 +804,6 @@ Translator *SelectTranslator(const char *name)
 		tr->langopts.accents = 2; // Say "Capital" after the letter.
 
 		tr->langopts.numbers = NUM_SINGLE_STRESS | NUM_DECIMAL_COMMA | NUM_ALLOW_SPACE | NUM_OMIT_1_HUNDRED | NUM_NOPAUSE | NUM_ROMAN | NUM_ROMAN_CAPITALS | NUM_ROMAN_AFTER | NUM_VIGESIMAL | NUM_DFRACTION_4;
-		SetLetterVowel(tr, 'y');
 	}
 		break;
 	case L('g', 'a'): // irish
@@ -900,8 +887,6 @@ Translator *SelectTranslator(const char *name)
 		tr->langopts.replace_chars = replace_cyrillic_latin;
 		tr->langopts.our_alphabet = OFFSET_CYRILLIC; // don't say "cyrillic" before letter names
 
-		SetLetterVowel(tr, 'y');
-		SetLetterVowel(tr, 'r');
 	}
 		break;
 	case L('h', 't'): // Haitian Creole
@@ -929,7 +914,6 @@ Translator *SelectTranslator(const char *name)
 		tr->langopts.decimal_sep = ',';
 		tr->langopts.max_roman = 899;
 		tr->langopts.min_roman = 1;
-		SetLetterVowel(tr, 'y');
 		tr->langopts.spelling_stress = 1;
 		SetLengthMods(tr, 3); // all equal
 	}
@@ -986,7 +970,6 @@ Translator *SelectTranslator(const char *name)
 		SetLetterBits(tr, 4, "kpst"); // Letter group F
 		SetLetterBits(tr, 3, "jvr"); // Letter group H
 		tr->letter_groups[1] = is_lettergroup_B;
-		SetLetterVowel(tr, 'y');
 		tr->langopts.numbers = NUM_DECIMAL_COMMA | NUM_SINGLE_AND | NUM_HUNDRED_AND | NUM_AND_UNITS | NUM_1900;
 		tr->langopts.numbers2 = 0x2;
 	}
@@ -1011,7 +994,6 @@ Translator *SelectTranslator(const char *name)
 		tr->langopts.numbers2 = NUM2_NO_TEEN_ORDINALS;
 		tr->langopts.roman_suffix = utf8_ordinal;
 		tr->langopts.accents = 2; // Say "Capital" after the letter.
-		SetLetterVowel(tr, 'y');
 	}
 		break;
 	case L_jbo: // Lojban
@@ -1024,7 +1006,6 @@ Translator *SelectTranslator(const char *name)
 		tr->langopts.vowel_pause = 0x20c; // pause before a word which starts with a vowel, or after a word which ends in a consonant
 		tr->punct_within_word = jbo_punct_within_word;
 		tr->langopts.param[LOPT_CAPS_IN_WORD] = 2; // capitals indicate stressed syllables
-		SetLetterVowel(tr, 'y');
 		tr->langopts.max_lengthmod = 368;
 	}
 		break;
@@ -1195,7 +1176,6 @@ Translator *SelectTranslator(const char *name)
 		tr->langopts.param[LOPT_DIERESES] = 1;
 		tr->langopts.param[LOPT_PREFIXES] = 1;
 		tr->langopts.param[LOPT_REGRESSIVE_VOICING] = 0x100; // devoice at end of word
-		SetLetterVowel(tr, 'y');
 
 		tr->langopts.numbers = NUM_DECIMAL_COMMA | NUM_SWAP_TENS | NUM_OMIT_1_HUNDRED | NUM_OMIT_1_THOUSAND | NUM_ALLOW_SPACE | NUM_1900 | NUM_ORDINAL_DOT;
 		tr->langopts.ordinal_indicator = "e";
@@ -1209,7 +1189,6 @@ Translator *SelectTranslator(const char *name)
 
 		SetupTranslator(tr, stress_lengths_no, NULL);
 		tr->langopts.stress_rule = STRESSPOSN_1L;
-		SetLetterVowel(tr, 'y');
 		tr->langopts.numbers = NUM_DECIMAL_COMMA | NUM_HUNDRED_AND | NUM_ALLOW_SPACE | NUM_1900 | NUM_ORDINAL_DOT;
 	}
 		break;
@@ -1240,7 +1219,6 @@ Translator *SelectTranslator(const char *name)
 		tr->langopts.numbers = NUM_DECIMAL_COMMA | NUM_ALLOW_SPACE | NUM_DFRACTION_2;
 		tr->langopts.numbers2 = NUM2_THOUSANDS_VAR3;
 		tr->langopts.param[LOPT_COMBINE_WORDS] = 4 + 0x100; // combine 'nie' (marked with $alt2) with some 1-syllable (and 2-syllable) words (marked with $alt)
-		SetLetterVowel(tr, 'y');
 	}
 		break;
 	case L('p', 't'): // Portuguese
@@ -1256,7 +1234,6 @@ Translator *SelectTranslator(const char *name)
 		tr->langopts.numbers = NUM_DECIMAL_COMMA | NUM_DFRACTION_2 | NUM_HUNDRED_AND | NUM_AND_UNITS | NUM_ROMAN_CAPITALS;
 		tr->langopts.numbers2 = NUM2_MULTIPLE_ORDINAL | NUM2_NO_TEEN_ORDINALS | NUM2_ORDINAL_NO_AND;
 		tr->langopts.max_roman = 5000;
-		SetLetterVowel(tr, 'y');
 		ResetLetterBits(tr, 0x2);
 		SetLetterBits(tr, 1, "bcdfgjkmnpqstvxz"); // B  hard consonants, excluding h,l,r,w,y
 		tr->langopts.param[LOPT_ALT] = 2; // call ApplySpecialAttributes2() if a word has $alt or $alt2
@@ -1314,8 +1291,6 @@ Translator *SelectTranslator(const char *name)
 		if (name2 == L('c', 's'))
 			tr->langopts.numbers2 = 0x108; // variant numbers before milliards
 
-		SetLetterVowel(tr, 'y');
-		SetLetterVowel(tr, 'r');
 		ResetLetterBits(tr, 0x20);
 		SetLetterBits(tr, 5, sk_voiced);
 	}
@@ -1368,7 +1343,6 @@ Translator *SelectTranslator(const char *name)
 
 		tr->langopts.stress_rule = STRESSPOSN_1R;
 		tr->langopts.stress_flags =  S_FINAL_DIM_ONLY | S_FINAL_NO_2 | S_FINAL_VOWEL_UNSTRESSED;
-		SetLetterVowel(tr, 'y');
 		tr->langopts.numbers = NUM_DECIMAL_COMMA | NUM_HUNDRED_AND | NUM_AND_UNITS | NUM_DFRACTION_4;
 		tr->langopts.accents = 2; // "capital" after letter name
 	}
@@ -1380,7 +1354,6 @@ Translator *SelectTranslator(const char *name)
 		SetupTranslator(tr, stress_lengths_sv, stress_amps_sv);
 
 		tr->langopts.stress_rule = STRESSPOSN_1L;
-		SetLetterVowel(tr, 'y');
 		tr->langopts.numbers = NUM_SINGLE_STRESS | NUM_DECIMAL_COMMA | NUM_ALLOW_SPACE | NUM_1900;
 		tr->langopts.accents = 1;
 	}
diff --git a/src/libespeak-ng/voices.c b/src/libespeak-ng/voices.c
index 6aed8c25..2b551dcc 100644
--- a/src/libespeak-ng/voices.c
+++ b/src/libespeak-ng/voices.c
@@ -109,7 +109,11 @@ enum {
 
 	// these need a phoneme table to have been specified
 	V_REPLACE,
-	V_CONSONANTS
+	V_CONSONANTS,
+
+	// these are alpha features that need to be tested and categorized
+	V_LETTER_VOWEL
+
 };
 
 static MNEM_TAB options_tab[] = {
@@ -168,6 +172,8 @@ static MNEM_TAB keyword_tab[] = {
 	{ "l_length_mods",    0x100+LOPT_LENGTH_MODS },
 	{ "apostrophe",       0x100+LOPT_APOSTROPHE },
 
+	// these are alpha features that need to be tested and categorized
+	{ "letterVowel", V_LETTER_VOWEL },
 	{ NULL, 0 }
 };
 
@@ -858,6 +864,27 @@ voice_t *LoadVoice(const char *vname, int control)
 		case V_MAINTAINER:
 		case V_STATUS:
 			break;
+
+		case V_LETTER_VOWEL: {
+			char str[5] = "";
+			char c = '0';
+			char *endptr = NULL;
+			sscanf(p, "%s", str);
+			// assume a hex value if string starts with "0x"
+			if (str[0] == '0' && str[1] == 'x') {
+				c = strtoul(str, &endptr, 16);
+				if (errno == ERANGE)
+					fprintf(stderr, "letterVowel out of range.\n");
+			}
+			else  {// otherwise, assume a single letter
+				c = str[0];
+				if (c < 97 || c > 122) // valid values are a-z, ascii 97-122
+					fprintf(stderr, "letterVowel out of range.\n");
+			}
+ 			new_translator->letter_bits[c] = (new_translator->letter_bits[c] & 0x40) | 0x81; // keep value for group 6 (front vowels e,i,y)
+			break;
+			}
+
 		default:
 			if ((key & 0xff00) == 0x100) {
 				if (langopts)