diff --git a/tools/chatgui-android/audio-probe/src/main/cpp/probe.cpp b/tools/chatgui-android/audio-probe/src/main/cpp/probe.cpp
index f2f5ac65..2e4b07bb 100644
--- a/tools/chatgui-android/audio-probe/src/main/cpp/probe.cpp
+++ b/tools/chatgui-android/audio-probe/src/main/cpp/probe.cpp
@@ -54,7 +54,7 @@ extern "C" JNIEXPORT void JNICALL Java_com_utun_audioprobe_ProbeActivity_closeNa
 }
 
 extern "C" JNIEXPORT jboolean JNICALL Java_com_utun_audioprobe_ProbeActivity_openNative(
-    JNIEnv*, jclass, jboolean exclusive, jint channels) {
+    JNIEnv*, jclass, jboolean exclusive, jint channels, jboolean callback) {
     if (probe.stream || (channels != 1 && channels != 2)) {
         DEBUG_ERROR(DEBUG_CATEGORY_CALL, "probe invalid open stream=%p channels=%d", probe.stream, channels);
         return JNI_FALSE;
@@ -70,7 +70,7 @@ extern "C" JNIEXPORT jboolean JNICALL Java_com_utun_audioprobe_ProbeActivity_ope
     AAudioStreamBuilder_setChannelCount(builder, channels);
     AAudioStreamBuilder_setSharingMode(builder, exclusive ? AAUDIO_SHARING_MODE_EXCLUSIVE : AAUDIO_SHARING_MODE_SHARED);
     AAudioStreamBuilder_setPerformanceMode(builder, AAUDIO_PERFORMANCE_MODE_LOW_LATENCY);
-    AAudioStreamBuilder_setDataCallback(builder, data_callback, &probe);
+    if (callback) AAudioStreamBuilder_setDataCallback(builder, data_callback, &probe);
     AAudioStreamBuilder_setErrorCallback(builder, error_callback, &probe);
     aaudio_result_t opened = AAudioStreamBuilder_openStream(builder, &probe.stream);
     check_result("delete builder", AAudioStreamBuilder_delete(builder));
@@ -99,6 +99,12 @@ extern "C" JNIEXPORT jboolean JNICALL Java_com_utun_audioprobe_ProbeActivity_ope
     return JNI_TRUE;
 }
 
+extern "C" JNIEXPORT jint JNICALL Java_com_utun_audioprobe_ProbeActivity_writeNative(JNIEnv* env, jclass, jshortArray input) {
+    int16_t samples[960]{};
+    env->GetShortArrayRegion(input, 0, 960, samples);
+    return AAudioStream_write(probe.stream, samples, 960 / probe.channels, 0);
+}
+
 /* Timestamp опрашивается вне realtime callback. Java одинаково агрегирует AAudio и AudioTrack. */
 extern "C" JNIEXPORT void JNICALL Java_com_utun_audioprobe_ProbeActivity_sampleNative(JNIEnv* env, jclass, jlongArray output) {
     if (!probe.stream || env->GetArrayLength(output) != 10) {
diff --git a/tools/chatgui-android/audio-probe/src/main/java/com/utun/audioprobe/ProbeActivity.java b/tools/chatgui-android/audio-probe/src/main/java/com/utun/audioprobe/ProbeActivity.java
index 7bca04ad..aac7b103 100644
--- a/tools/chatgui-android/audio-probe/src/main/java/com/utun/audioprobe/ProbeActivity.java
+++ b/tools/chatgui-android/audio-probe/src/main/java/com/utun/audioprobe/ProbeActivity.java
@@ -24,7 +24,8 @@ import java.util.concurrent.atomic.AtomicLong;
 public final class ProbeActivity extends Activity {
     private static final String TAG = "AudioProbe";
     static { System.loadLibrary("call_audio_probe"); }
-    private static native boolean openNative(boolean exclusive, int channels);
+    private static native boolean openNative(boolean exclusive, int channels, boolean callback);
+    private static native int writeNative(short[] input);
     private static native void sampleNative(long[] out);
     private static native void closeNative();
     private volatile boolean cancelled;
@@ -143,10 +144,31 @@ public final class ProbeActivity extends Activity {
 
     private Output open(int mode, int channels) {
         if (mode == 0) return new TrackOutput();
-        if (!openNative(mode == 2, channels)) throw new IllegalStateException("AAudio open rejected");
+        boolean callback = getIntent().getBooleanExtra("callback", true);
+        if (!openNative(mode == 2, channels, callback)) throw new IllegalStateException("AAudio open rejected");
+        AtomicInteger writeError = new AtomicInteger();
+        java.util.concurrent.atomic.AtomicBoolean writing = new java.util.concurrent.atomic.AtomicBoolean(!callback);
+        Thread writer = new Thread(() -> {
+            short[] silence = new short[960];
+            try {
+                while (writing.get() && !cancelled) {
+                    int n = writeNative(silence);
+                    if (n < 0) { writeError.set(n); Log.e(TAG, "AAudio write=" + n); break; }
+                    if (n == 0) Thread.sleep(2);
+                }
+            } catch (InterruptedException e) { Thread.currentThread().interrupt(); }
+        }, "audio-probe-aaudio-write");
+        if (!callback) writer.start();
         return new Output() {
-            public void sample(long[] out) { sampleNative(out); }
-            public void close() { closeNative(); }
+            public void sample(long[] out) { sampleNative(out); if (writeError.get() != 0) out[7] = writeError.get(); }
+            public void close() {
+                writing.set(false);
+                if (!callback) {
+                    writer.interrupt();
+                    try { writer.join(); } catch (InterruptedException e) { Thread.currentThread().interrupt(); Log.e(TAG, "AAudio join", e); }
+                }
+                closeNative();
+            }
         };
     }