diff --git a/tools/chatgui/src/sound_manager.cpp b/tools/chatgui/src/sound_manager.cpp
index 36d8ec82..c2eedcb8 100644
--- a/tools/chatgui/src/sound_manager.cpp
+++ b/tools/chatgui/src/sound_manager.cpp
@@ -164,7 +164,8 @@ unsigned SoundManager::renderOutput(ma_engine* engine, const std::array<VoiceAud
         if (engine && ma_engine_read_pcm_frames(engine, destination, count, nullptr) != MA_SUCCESS) {
             ++errors; std::fill_n(destination, count * 2, 0.0f);
         }
-        for (auto* voice : voices) if (voice) voice->mix(destination, count, firstTimeUs + (int64_t)offset * 1000000 / 48000, measured);
+        for (auto* voice : voices) if (voice)
+            voice->mix(destination, count, firstTimeUs + (int64_t)offset * 1000000 / 48000, measured, frames);
         for (unsigned i = 0; i < count * 2; ++i) {
             float value = destination[i];
             destination[i] = std::isfinite(value) ? std::clamp(value, -1.0f, 1.0f) : 0.0f;
diff --git a/tools/chatgui/src/voice_audio_io.cpp b/tools/chatgui/src/voice_audio_io.cpp
index e15ea6bb..bcb16f73 100644
--- a/tools/chatgui/src/voice_audio_io.cpp
+++ b/tools/chatgui/src/voice_audio_io.cpp
@@ -177,6 +177,7 @@ void VoiceAudioIo::playbackLoop() {
     unsigned missing = 0;
     VoicePlaybackBuffer buffering;
     PlaybackProgress lastProgress{};
+    int64_t lastProgressUs = 0;
     call_clock_snapshot clock{};
     if (m_kind == Kind::Call && call_audio_get_clock(m_session, voice_time_us(), &clock) != 0)
         DEBUG_WARN(DEBUG_CATEGORY_CALL, "voice-io: call clock unavailable session=%llu", (unsigned long long)m_session);
@@ -210,6 +211,7 @@ void VoiceAudioIo::playbackLoop() {
             queueUs.add(int64_t(progress.queuedFrames) * 1000000 / 48000);
             missing += progress.missing;
             lastProgress = progress;
+            lastProgressUs = voice_time_us();
             if (!progress.consumed) continue;
             int64_t now = voice_time_us(), remaining = progress.endTimeUs - now;
             if (m_kind == Kind::Call)
@@ -259,7 +261,7 @@ void VoiceAudioIo::playbackLoop() {
             int64_t queuedUs = (position - lastProgress.position) * 1000000 / 48000;
             std::lock_guard lock(m_latencyMutex);
             m_outputLatency = {int(queuedUs / 1000), int((queuedUs + std::max(lastProgress.endTimeUs - now, int64_t(0))) / 1000),
-                               lastProgress.measured, now};
+                               lastProgress.measured, lastProgressUs};
         }
     }
 }
diff --git a/tools/chatgui/tests/test_voice_audio_io.cpp b/tools/chatgui/tests/test_voice_audio_io.cpp
index d140ade7..5fbc3c32 100644
--- a/tools/chatgui/tests/test_voice_audio_io.cpp
+++ b/tools/chatgui/tests/test_voice_audio_io.cpp
@@ -1,6 +1,7 @@
 /* Настоящие workers/AEC; граница сервисного PCM заменена наблюдателями без сети/устройства. */
 #include "../src/voice_audio_io.h"
 #include "../src/voice_capture_clock.h"
+#include "../src/voice_playback_buffer.h"
 extern "C" {
 #include "call/call_audio.h"
 #include "radio/radio_audio.h"
@@ -74,6 +75,18 @@ static void reset() {
 }
 int main() {
     debug_config_init(); debug_set_level(DEBUG_LEVEL_WARN);
+    // Резерв уменьшается только при стабильной работе; крупный callback и starvation повышают минимум.
+    VoicePlaybackBuffer buffering;
+    buffering.sample(1, 512, false);
+    buffering.sample(10000000, 512, false); REQUIRE(buffering.blocks == 2);
+    buffering.sample(10000001, 512, false); REQUIRE(buffering.blocks == 1);
+    buffering.sample(10020001, 512, true); REQUIRE(buffering.blocks == 2);
+    buffering.sample(10020002, 512, true); REQUIRE(buffering.blocks == 2);
+    buffering.sample(10520001, 512, true); REQUIRE(buffering.blocks == 3);
+    buffering.sample(20520001, 2048, false); REQUIRE(buffering.blocks == 3);
+    buffering.sample(30520001, 512, false); REQUIRE(buffering.blocks == 2);
+    buffering.sample(40520001, 512, false); REQUIRE(buffering.blocks == 1);
+    buffering.reset(); REQUIRE(buffering.blocks == 2);
     // Десять минут +/-300ppm дрейфа: связь с физическим временем сохраняется, шага >2мс нет.
     for (double drift : {-0.0003, 0.0003}) {
         VoiceCaptureClock clock;
@@ -106,9 +119,12 @@ int main() {
     voice.mix(partial, 240, now_us() + 500000);
     await([] { return output_position.load() == 240; });
     REQUIRE(output_delay > 4500);
+    auto latency = voice.outputLatency();
+    REQUIRE(latency.outputMs >= latency.queueMs + 450);
     voice.mix(partial, 720, now_us());
     await([] { return output_position.load() == 960; });
     voice.stop();
+    REQUIRE(voice.outputLatency().outputMs == -1);
     voice.start(VoiceAudioIo::Kind::Radio, 7); REQUIRE(voice.startCapture(1, false));
     voice.capture(pcm.data(), 240, 0); voice.setPtt(true);
     voice.capture(pcm.data(), 360, 0); voice.setPtt(false); voice.capture(pcm.data(), 360, 0);