diff --git a/pythainlp/util/syllable.py b/pythainlp/util/syllable.py
index 58eef09f..c3733acb 100644
--- a/pythainlp/util/syllable.py
+++ b/pythainlp/util/syllable.py
@@ -81,8 +81,23 @@ def sound_syllable(syllable: str) -> str:
         print(sound_syllable("เลข"))
         # output: dead
     """
-    # get consonants
-    consonants = [i for i in syllable if i in list(thai_consonants_all)]
+    # get consonants, ignoring sonorants ร,ล that are part of initial cluster
+    consonants = []
+    for idx, ch in enumerate(syllable):
+        if ch in list(thai_consonants_all):
+            # ignore sonorant ร or ล if it is preceded by a consonant and followed by a vowel
+            if ch in ("ร", "ล"):
+                if idx > 0 and syllable[idx - 1] in list(thai_consonants_all):
+                    # check if followed by a vowel (non-consonant and not tone mark?)
+                    if idx + 1 < len(syllable):
+                        nxt = syllable[idx + 1]
+                        if nxt not in list(thai_consonants_all):
+                            # likely a vowel or tone mark, treat as cluster, skip this sonorant
+                            continue
+            consonants.append(ch)
+    # if no consonants, treat as live (vowel-only syllable)
+    if not consonants:
+        return "live"
     # get spelling consonants
     spelling_consonant = consonants[-1]
     # if len of syllable < 2
@@ -241,6 +256,9 @@ def tone_detector(syllable: str) -> str:
     s = sound_syllable(syllable)
     # get consonants
     consonants = [i for i in syllable if i in list(thai_consonants)]
+    if not consonants:
+        # vowel-only syllable, default to mid tone
+        return "m"
     initial_consonant = consonants[0]
     tone_mark = _tone_mark_detector(syllable)
     syllable_check = syllable_open_close_detector(syllable)