diff --git a/tools/chatgui-android/app/src/main/java/com/utun/chat/data/AudioRecorderManager.kt b/tools/chatgui-android/app/src/main/java/com/utun/chat/data/AudioRecorderManager.kt
index ca8e686b..9d55ce28 100644
--- a/tools/chatgui-android/app/src/main/java/com/utun/chat/data/AudioRecorderManager.kt
+++ b/tools/chatgui-android/app/src/main/java/com/utun/chat/data/AudioRecorderManager.kt
@@ -82,8 +82,14 @@ class AudioRecorderManager {
             var totalRead = 0L
 
             while (isRecording && device.recordingState == AudioRecord.RECORDSTATE_RECORDING) {
-                val read = device.read(buffer, 0, FRAME_SAMPLES)
-                if (read <= 0) break
+                val read = try { device.read(buffer, 0, FRAME_SAMPLES) } catch (e: Exception) {
+                    if (isRecording) LogManager.addLog("ERROR", "AudioRecorder", "capture read failed: ${e.message}")
+                    break
+                }
+                if (read <= 0) {
+                    if (isRecording) LogManager.addLog("ERROR", "AudioRecorder", "capture read failed code=$read")
+                    break
+                }
                 NativeLib.voiceFeed(buffer.copyOf(read))
                 totalRead += read
             }
@@ -101,7 +107,7 @@ class AudioRecorderManager {
         isRecording = false
 
         audioRecord?.apply {
-            try { stop() } catch (_: Exception) {}
+            try { stop() } catch (e: Exception) { LogManager.addLog("WARN", "AudioRecorder", "capture stop failed: ${e.message}") }
         }
         recordingThread?.join()
         recordingThread = null
@@ -118,7 +124,7 @@ class AudioRecorderManager {
         isRecording = false
 
         audioRecord?.apply {
-            try { stop() } catch (_: Exception) {}
+            try { stop() } catch (e: Exception) { LogManager.addLog("WARN", "AudioRecorder", "capture cancel failed: ${e.message}") }
         }
         recordingThread?.join()
         recordingThread = null
diff --git a/tools/chatgui-android/libutun_lite/voice_recorder.c b/tools/chatgui-android/libutun_lite/voice_recorder.c
index 90258914..42cec5a4 100644
--- a/tools/chatgui-android/libutun_lite/voice_recorder.c
+++ b/tools/chatgui-android/libutun_lite/voice_recorder.c
@@ -40,9 +40,6 @@ struct voice_recorder {
     int preset;
 
     float peak_level;
-    float waveform_levels[100];
-    int   waveform_count;
-    int64_t next_wf_time_ms;
 
     int64_t start_time_ms;
 };
@@ -110,6 +107,10 @@ void voice_recorder_deinit(void) {
 }
 
 int voice_recorder_start(const char* channel_id, int sample_rate, int channels) {
+    if (!channel_id || !channel_id[0] || strlen(channel_id) >= 64 || sample_rate != 48000 || channels != 1) {
+        DEBUG_ERROR(DEBUG_CATEGORY_MEDIA, "voice start: invalid target or capture format rate=%d channels=%d", sample_rate, channels);
+        return -1;
+    }
     pthread_mutex_lock(&g_init_mtx);
     if (!g_rec) {
         DEBUG_ERROR(DEBUG_CATEGORY_GENERAL, "voice_recorder_start: not initialized (g_rec=NULL)");
@@ -124,8 +125,6 @@ int voice_recorder_start(const char* channel_id, int sample_rate, int channels)
         return -1;
     }
 
-    if (sample_rate <= 0) sample_rate = 48000;
-    if (channels <= 0) channels = 1;
     g_rec->sample_rate = sample_rate;
     g_rec->channels = channels;
     g_rec->frame_samples = sample_rate * FRAME_MS / 1000;
@@ -133,8 +132,6 @@ int voice_recorder_start(const char* channel_id, int sample_rate, int channels)
 
     g_rec->pcm_count = 0;
     g_rec->active = 1;
-    g_rec->waveform_count = 0;
-    g_rec->next_wf_time_ms = 0;
 
     struct timespec ts; clock_gettime(CLOCK_MONOTONIC, &ts);
     g_rec->start_time_ms = ts.tv_sec * 1000LL + ts.tv_nsec / 1000000LL;
@@ -165,14 +162,6 @@ int voice_recorder_feed(const int16_t* samples, int count) {
             sum_sq += v * v; float av = fabsf(v); if (av > peak) peak = av;
         }
         g_rec->peak_level = (sqrtf(sum_sq / (float)count) * 2.0f + peak) / 2.0f;
-
-        /* accumulate waveform level every ~100ms */
-        {   int64_t now = now_ms();
-            if (g_rec->waveform_count < 100 && now >= g_rec->next_wf_time_ms) {
-                g_rec->waveform_levels[g_rec->waveform_count++] = g_rec->peak_level;
-                g_rec->next_wf_time_ms = now + 100;
-            }
-        }
     }
 
     if (g_rec->compressor && g_rec->compressor_enabled) {
@@ -228,6 +217,7 @@ int voice_recorder_stop(int* out_duration_ms) {
     if (g_rec->compressor && g_rec->compressor_enabled) {
         struct audio_compressor* replacement = audio_compressor_clone_config(g_rec->compressor);
         if (!replacement) {
+            DEBUG_ERROR(DEBUG_CATEGORY_MEDIA, "voice stop: replacement compressor allocation failed");
             u_free(req); u_free(post); voice_cleanup_locked(g_rec);
             pthread_mutex_unlock(&g_rec->mtx); pthread_mutex_unlock(&g_init_mtx); return -1;
         }