diff --git a/webrtc/common_audio/wav_writer_unittest.cc b/webrtc/common_audio/wav_writer_unittest.cc
new file mode 100644
index 0000000..9efe96e
--- /dev/null
+++ b/webrtc/common_audio/wav_writer_unittest.cc
@@ -0,0 +1,124 @@
+/*
+ *  Copyright (c) 2014 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+// MSVC++ requires this to be set before any other includes to get M_PI.
+#define _USE_MATH_DEFINES
+
+#include <cmath>
+#include <limits>
+
+#include "testing/gtest/include/gtest/gtest.h"
+#include "webrtc/base/compile_assert.h"
+#include "webrtc/common_audio/wav_header.h"
+#include "webrtc/common_audio/wav_writer.h"
+#include "webrtc/test/testsupport/fileutils.h"
+
+static const float kSamples[] = {0.0, 10.0, 4e4, -1e9};
+
+// Write a tiny WAV file with the C++ interface and verify the result.
+TEST(WavWriterTest, CPP) {
+  const std::string outfile = webrtc::test::OutputPath() + "wavtest1.wav";
+  static const int kNumSamples = 3;
+  {
+    webrtc::WavFile w(outfile, 14099, 1);
+    w.WriteSamples(kSamples, kNumSamples);
+  }
+  static const uint8_t kExpectedContents[] = {
+    'R', 'I', 'F', 'F',
+    42, 0, 0, 0,  // size of whole file - 8: 6 + 44 - 8
+    'W', 'A', 'V', 'E',
+    'f', 'm', 't', ' ',
+    16, 0, 0, 0,  // size of fmt block - 8: 24 - 8
+    1, 0,  // format: PCM (1)
+    1, 0,  // channels: 1
+    0x13, 0x37, 0, 0,  // sample rate: 14099
+    0x26, 0x6e, 0, 0,  // byte rate: 2 * 14099
+    2, 0,  // block align: NumChannels * BytesPerSample
+    16, 0,  // bits per sample: 2 * 8
+    'd', 'a', 't', 'a',
+    6, 0, 0, 0,  // size of payload: 6
+    0, 0,  // first sample: 0.0
+    10, 0,  // second sample: 10.0
+    0xff, 0x7f,  // third sample: 4e4 (saturated)
+  };
+  static const int kContentSize =
+      webrtc::kWavHeaderSize + kNumSamples * sizeof(int16_t);
+  COMPILE_ASSERT(sizeof(kExpectedContents) == kContentSize, content_size);
+  EXPECT_EQ(size_t(kContentSize), webrtc::test::GetFileSize(outfile));
+  FILE* f = fopen(outfile.c_str(), "rb");
+  ASSERT_TRUE(f);
+  uint8_t contents[kContentSize];
+  ASSERT_EQ(1u, fread(contents, kContentSize, 1, f));
+  EXPECT_EQ(0, fclose(f));
+  EXPECT_EQ(0, memcmp(kExpectedContents, contents, kContentSize));
+}
+
+// Write a tiny WAV file with the C interface and verify the result.
+TEST(WavWriterTest, C) {
+  const std::string outfile = webrtc::test::OutputPath() + "wavtest2.wav";
+  rtc_WavFile *w = rtc_WavOpen(outfile.c_str(), 11904, 2);
+  static const int kNumSamples = 4;
+  rtc_WavWriteSamples(w, &kSamples[0], 2);
+  rtc_WavWriteSamples(w, &kSamples[2], kNumSamples - 2);
+  rtc_WavClose(w);
+  static const uint8_t kExpectedContents[] = {
+    'R', 'I', 'F', 'F',
+    44, 0, 0, 0,  // size of whole file - 8: 8 + 44 - 8
+    'W', 'A', 'V', 'E',
+    'f', 'm', 't', ' ',
+    16, 0, 0, 0,  // size of fmt block - 8: 24 - 8
+    1, 0,  // format: PCM (1)
+    2, 0,  // channels: 2
+    0x80, 0x2e, 0, 0,  // sample rate: 11904
+    0, 0xba, 0, 0,  // byte rate: 2 * 2 * 11904
+    4, 0,  // block align: NumChannels * BytesPerSample
+    16, 0,  // bits per sample: 2 * 8
+    'd', 'a', 't', 'a',
+    8, 0, 0, 0,  // size of payload: 8
+    0, 0,  // first sample: 0.0
+    10, 0,  // second sample: 10.0
+    0xff, 0x7f,  // third sample: 4e4 (saturated)
+    0, 0x80,  // fourth sample: -1e9 (saturated)
+  };
+  static const int kContentSize =
+      webrtc::kWavHeaderSize + kNumSamples * sizeof(int16_t);
+  COMPILE_ASSERT(sizeof(kExpectedContents) == kContentSize, content_size);
+  EXPECT_EQ(size_t(kContentSize), webrtc::test::GetFileSize(outfile));
+  FILE* f = fopen(outfile.c_str(), "rb");
+  ASSERT_TRUE(f);
+  uint8_t contents[kContentSize];
+  ASSERT_EQ(1u, fread(contents, kContentSize, 1, f));
+  EXPECT_EQ(0, fclose(f));
+  EXPECT_EQ(0, memcmp(kExpectedContents, contents, kContentSize));
+}
+
+// Write a larger WAV file. You can listen to this file to sanity-check it.
+TEST(WavWriterTest, LargeFile) {
+  std::string outfile = webrtc::test::OutputPath() + "wavtest3.wav";
+  static const int kSampleRate = 8000;
+  static const int kNumChannels = 2;
+  static const int kNumSamples = 3 * kSampleRate * kNumChannels;
+  float samples[kNumSamples];
+  for (int i = 0; i < kNumSamples; i += kNumChannels) {
+    // A nice periodic beeping sound.
+    static const double kToneHz = 440;
+    const double t = static_cast<double>(i) / (kNumChannels * kSampleRate);
+    const double x =
+        std::numeric_limits<int16_t>::max() * std::sin(t * kToneHz * 2 * M_PI);
+    samples[i] = std::pow(std::sin(t * 2 * 2 * M_PI), 10) * x;
+    samples[i + 1] = std::pow(std::cos(t * 2 * 2 * M_PI), 10) * x;
+  }
+  {
+    webrtc::WavFile w(outfile, kSampleRate, kNumChannels);
+    w.WriteSamples(samples, kNumSamples);
+  }
+  EXPECT_EQ(sizeof(int16_t) * kNumSamples + webrtc::kWavHeaderSize,
+            webrtc::test::GetFileSize(outfile));
+}