Index: uspace/lib/pcm/include/pcm/format.h
===================================================================
--- uspace/lib/pcm/include/pcm/format.h	(revision ea6c83870417e73e052e92cb12eed894e739dbca)
+++ uspace/lib/pcm/include/pcm/format.h	(revision e6bba8f1a67abc65679b29789926d859e94458f9)
@@ -69,4 +69,5 @@
 	return pcm_format_same(f, &AUDIO_FORMAT_ANY);
 }
+void pcm_format_silence(void *dst, size_t size, const pcm_format_t *f);
 int pcm_format_convert_and_mix(void *dst, size_t dst_size, const void *src,
     size_t src_size, const pcm_format_t *sf, const pcm_format_t *df);
Index: uspace/lib/pcm/src/format.c
===================================================================
--- uspace/lib/pcm/src/format.c	(revision ea6c83870417e73e052e92cb12eed894e739dbca)
+++ uspace/lib/pcm/src/format.c	(revision e6bba8f1a67abc65679b29789926d859e94458f9)
@@ -86,4 +86,50 @@
 	    a->channels == b->channels &&
 	    a->sample_format == b->sample_format;
+}
+
+void pcm_format_silence(void *dst, size_t size, const pcm_format_t *f)
+{
+#define SET_NULL(type, endian, nullv) \
+do { \
+	type *buffer = dst; \
+	const size_t sample_count = size / sizeof(type); \
+	for (unsigned i = 0; i < sample_count; ++i) { \
+		buffer[i] = to((type)nullv, type, endian); \
+	} \
+} while (0)
+
+	switch (f->sample_format) {
+	case PCM_SAMPLE_UINT8:
+		SET_NULL(uint8_t, le, INT8_MIN); break;
+	case PCM_SAMPLE_SINT8:
+		SET_NULL(int8_t, le, 0); break;
+	case PCM_SAMPLE_UINT16_LE:
+		SET_NULL(uint16_t, le, INT16_MIN); break;
+	case PCM_SAMPLE_SINT16_LE:
+		SET_NULL(int16_t, le, 0); break;
+	case PCM_SAMPLE_UINT16_BE:
+		SET_NULL(uint16_t, be, INT16_MIN); break;
+	case PCM_SAMPLE_SINT16_BE:
+		SET_NULL(int16_t, be, 0); break;
+	case PCM_SAMPLE_UINT32_LE:
+		SET_NULL(uint32_t, le, INT32_MIN); break;
+	case PCM_SAMPLE_SINT32_LE:
+		SET_NULL(int32_t, le, 0); break;
+	case PCM_SAMPLE_UINT32_BE:
+		SET_NULL(uint32_t, be, INT32_MIN); break;
+	case PCM_SAMPLE_SINT32_BE:
+		SET_NULL(int32_t, le, 0); break;
+	case PCM_SAMPLE_UINT24_32_LE:
+	case PCM_SAMPLE_SINT24_32_LE:
+	case PCM_SAMPLE_UINT24_32_BE:
+	case PCM_SAMPLE_SINT24_32_BE:
+	case PCM_SAMPLE_UINT24_LE:
+	case PCM_SAMPLE_SINT24_LE:
+	case PCM_SAMPLE_UINT24_BE:
+	case PCM_SAMPLE_SINT24_BE:
+	case PCM_SAMPLE_FLOAT32:
+	default: ;
+	}
+#undef SET_NULL
 }