diff --git a/samples/audioProfile.js b/samples/audioProfile.js
index aef6297a..e995493a 100644
--- a/samples/audioProfile.js
+++ b/samples/audioProfile.js
@@ -14,8 +14,7 @@
  */
 
 'use strict';
-
-function synthesizeText(
+async function synthesizeText(
   text,
   outputFile,
   effectsProfileId,
@@ -27,6 +26,7 @@ function synthesizeText(
   // Imports the Google Cloud client library
   const speech = require('@google-cloud/text-to-speech');
   const fs = require('fs');
+  const util = require('util');
 
   // Creates a client
   const client = new speech.TextToSpeechClient();
@@ -37,91 +37,85 @@ function synthesizeText(
     audioConfig: {audioEncoding: 'MP3', effectsProfileId: effectsProfileId},
   };
 
-  client.synthesizeSpeech(request, (err, response) => {
-    if (err) {
-      console.error(`ERROR:`, err);
-      return;
-    }
-
-    fs.writeFile(outputFile, response.audioContent, 'binary', err => {
-      if (err) {
-        console.error('ERROR:', err);
-        return;
-      }
-      console.log(`Audio content written to file: ${outputFile}`);
-    });
-  });
+  const [response] = await client.synthesizeSpeech(request);
+  const writeFile = util.promisify(fs.writeFile);
+  await writeFile(outputFile, response.audioContent, 'binary');
+  console.log(`Audio content written to file: ${outputFile}`);
   // [END tts_synthesize_text_audio_profile_beta]
 }
 
-require(`yargs`)
-  .demand(1)
-  .command(
-    `synthesize <text>`,
-    `Detects speech in a local audio file.`,
-    {},
-    opts =>
-      synthesizeText(
-        opts.text,
-        opts.outputFile,
-        opts.effectsProfileId,
-        opts.languageCode,
-        opts.ssmlGender
-      )
-  )
-  .options({
-    text: {
-      alias: 't',
-      default: 'Hey Everybody!  This is a test!',
-      global: true,
-      requiresArg: true,
-      type: 'string',
-    },
-    outputFile: {
-      alias: 'f',
-      default: './resources/test.mp3',
-      global: true,
-      requiresArg: false,
-      type: 'string',
-    },
-    effectsProfileId: {
-      alias: 'e',
-      default: 'telephony-class-application',
-      global: true,
-      requiresArg: true,
-      type: 'string',
-    },
-    languageCode: {
-      alias: 'l',
-      default: 'en-US',
-      global: true,
-      requiresArg: true,
-      tnodeype: 'string',
-    },
-    ssmlGender: {
-      alias: 'g',
-      default: 'FEMALE',
-      global: true,
-      requiresArg: true,
-      type: 'string',
-    },
-  })
-  .array(`effectsProfileId`)
-  .example(`node $0 synthesize "Enter Phrase to Test Here"`)
-  .example(
-    `node $0 synthesize "This is optimized for Phone" -f ./resources/phone.mp3 -e telephony-class-application -l en-US`
-  )
-  .example(
-    `node $0 synthesize "This is optimized for a Wearable, like a watch" -f ./resources/watch.mp3 -e wearable-class-device -l en-US`
-  )
-  .example(
-    `node $0 synthesize "This is optimized for Home Entertainment System" -f ./resources/homestereo.mp3 -e large-home-entertainment-class-device`
-  )
-  .example(
-    `node $0 synthesize "This is optimized for the Car" -f ./resources/car.mp3 -e large-automotive-class-device`
-  )
-  .wrap(120)
-  .recommendCommands()
-  .epilogue(`For more information, see https://cloud.google.com/speech/docs`)
-  .help()
-  .strict().argv;
+async function main() {
+  require(`yargs`)
+    .demand(1)
+    .command(
+      `synthesize <text>`,
+      `Detects speech in a local audio file.`,
+      {},
+      opts =>
+        synthesizeText(
+          opts.text,
+          opts.outputFile,
+          opts.effectsProfileId,
+          opts.languageCode,
+          opts.ssmlGender
+        )
+    )
+    .options({
+      text: {
+        alias: 't',
+        default: 'Hey Everybody!  This is a test!',
+        global: true,
+        requiresArg: true,
+        type: 'string',
+      },
+      outputFile: {
+        alias: 'f',
+        default: './resources/test.mp3',
+        global: true,
+        requiresArg: false,
+        type: 'string',
+      },
+      effectsProfileId: {
+        alias: 'e',
+        default: 'telephony-class-application',
+        global: true,
+        requiresArg: true,
+        type: 'string',
+      },
+      languageCode: {
+        alias: 'l',
+        default: 'en-US',
+        global: true,
+        requiresArg: true,
+        tnodeype: 'string',
+      },
+      ssmlGender: {
+        alias: 'g',
+        default: 'FEMALE',
+        global: true,
+        requiresArg: true,
+        type: 'string',
+      },
+    })
+    .array(`effectsProfileId`)
+    .example(`node $0 synthesize "Enter Phrase to Test Here"`)
+    .example(
+      `node $0 synthesize "This is optimized for Phone" -f ./resources/phone.mp3 -e telephony-class-application -l en-US`
+    )
+    .example(
+      `node $0 synthesize "This is optimized for a Wearable, like a watch" -f ./resources/watch.mp3 -e wearable-class-device -l en-US`
+    )
+    .example(
+      `node $0 synthesize "This is optimized for Home Entertainment System" -f ./resources/homestereo.mp3 -e large-home-entertainment-class-device`
+    )
+    .example(
+      `node $0 synthesize "This is optimized for the Car" -f ./resources/car.mp3 -e large-automotive-class-device`
+    )
+    .wrap(120)
+    .recommendCommands()
+    .epilogue(`For more information, see https://cloud.google.com/speech/docs`)
+    .help()
+    .strict().argv;
+}
+
+main().catch(console.error);
diff --git a/samples/listVoices.js b/samples/listVoices.js
index 28c31a0c..d6c98be3 100644
--- a/samples/listVoices.js
+++ b/samples/listVoices.js
@@ -15,44 +15,40 @@
 
 'use strict';
 
-function listVoices() {
+async function listVoices() {
   // [START tts_list_voices]
   const textToSpeech = require('@google-cloud/text-to-speech');
 
   const client = new textToSpeech.TextToSpeechClient();
 
-  client
-    .listVoices({})
-    .then(results => {
-      const voices = results[0].voices;
+  const [result] = await client.listVoices({});
+  const voices = result.voices;
 
-      console.log('Voices:');
-      voices.forEach(voice => {
-        console.log(`Name: ${voice.name}`);
-        console.log(`  SSML Voice Gender: ${voice.ssmlGender}`);
-        console.log(
-          `  Natural Sample Rate Hertz: ${voice.naturalSampleRateHertz}`
-        );
-        console.log(`  Supported languages:`);
-        voice.languageCodes.forEach(languageCode => {
-          console.log(`    ${languageCode}`);
-        });
-      });
-    })
-    .catch(err => {
-      console.error('ERROR:', err);
+  console.log('Voices:');
+  voices.forEach(voice => {
+    console.log(`Name: ${voice.name}`);
+    console.log(`  SSML Voice Gender: ${voice.ssmlGender}`);
+    console.log(`  Natural Sample Rate Hertz: ${voice.naturalSampleRateHertz}`);
+    console.log(`  Supported languages:`);
+    voice.languageCodes.forEach(languageCode => {
+      console.log(`    ${languageCode}`);
     });
+  });
   // [END tts_list_voices]
 }
 
+async function main() {
 require(`yargs`) // eslint-disable-line
-  .demand(1)
-  .command(`list-voices`, `List supported voices.`, {}, () => listVoices())
-  .example(`node $0 list-voices`)
-  .wrap(120)
-  .recommendCommands()
-  .epilogue(
-    `For more information, see https://cloud.google.com/text-to-speech/docs`
-  )
-  .help()
-  .strict().argv;
+    .demand(1)
+    .command(`list-voices`, `List supported voices.`, {}, () => listVoices())
+    .example(`node $0 list-voices`)
+    .wrap(120)
+    .recommendCommands()
+    .epilogue(
+      `For more information, see https://cloud.google.com/text-to-speech/docs`
+    )
+    .help()
+    .strict().argv;
+}
+
+main().catch(console.error);
diff --git a/samples/quickstart.js b/samples/quickstart.js
index 56d82e24..5ea3373c 100644
--- a/samples/quickstart.js
+++ b/samples/quickstart.js
@@ -15,41 +15,36 @@
 
 'use strict';
 
-// [START tts_quickstart]
-const fs = require('fs');
-
-// Imports the Google Cloud client library
-const textToSpeech = require('@google-cloud/text-to-speech');
-
-// Creates a client
-const client = new textToSpeech.TextToSpeechClient();
-
-// The text to synthesize
-const text = 'Hello, world!';
-
-// Construct the request
-const request = {
-  input: {text: text},
-  // Select the language and SSML Voice Gender (optional)
-  voice: {languageCode: 'en-US', ssmlGender: 'NEUTRAL'},
-  // Select the type of audio encoding
-  audioConfig: {audioEncoding: 'MP3'},
-};
-
-// Performs the Text-to-Speech request
-client.synthesizeSpeech(request, (err, response) => {
-  if (err) {
-    console.error('ERROR:', err);
-    return;
-  }
-
+async function main() {
+  // [START tts_quickstart]
+  const fs = require('fs');
+  const util = require('util');
+
+  // Imports the Google Cloud client library
+  const textToSpeech = require('@google-cloud/text-to-speech');
+
+  // Creates a client
+  const client = new textToSpeech.TextToSpeechClient();
+
+  // The text to synthesize
+  const text = 'Hello, world!';
+
+  // Construct the request
+  const request = {
+    input: {text: text},
+    // Select the language and SSML Voice Gender (optional)
+    voice: {languageCode: 'en-US', ssmlGender: 'NEUTRAL'},
+    // Select the type of audio encoding
+    audioConfig: {audioEncoding: 'MP3'},
+  };
+
+  // Performs the Text-to-Speech request
+  const [response] = await client.synthesizeSpeech(request);
   // Write the binary audio content to a local file
-  fs.writeFile('output.mp3', response.audioContent, 'binary', err => {
-    if (err) {
-      console.error('ERROR:', err);
-      return;
-    }
-    console.log('Audio content written to file: output.mp3');
-  });
-});
-// [END tts_quickstart]
+  const writeFile = util.promisify(fs.writeFile);
+  await writeFile('output.mp3', response.audioContent, 'binary');
+  console.log('Audio content written to file: output.mp3');
+  // [END tts_quickstart]
+}
+
+main().catch(console.error);
diff --git a/samples/synthesize.js b/samples/synthesize.js
index 556e1305..39057d0c 100644
--- a/samples/synthesize.js
+++ b/samples/synthesize.js
@@ -14,11 +14,11 @@
  */
 
 'use strict';
-
-function synthesizeText(text, outputFile) {
+async function synthesizeText(text, outputFile) {
   // [START tts_synthesize_text]
   const textToSpeech = require('@google-cloud/text-to-speech');
   const fs = require('fs');
+  const util = require('util');
 
   const client = new textToSpeech.TextToSpeechClient();
 
@@ -33,28 +33,18 @@ function synthesizeText(text, outputFile) {
     voice: {languageCode: 'en-US', ssmlGender: 'FEMALE'},
     audioConfig: {audioEncoding: 'MP3'},
   };
-
-  client.synthesizeSpeech(request, (err, response) => {
-    if (err) {
-      console.error('ERROR:', err);
-      return;
-    }
-
-    fs.writeFile(outputFile, response.audioContent, 'binary', err => {
-      if (err) {
-        console.error('ERROR:', err);
-        return;
-      }
-      console.log(`Audio content written to file: ${outputFile}`);
-    });
-  });
+  const [response] = await client.synthesizeSpeech(request);
+  const writeFile = util.promisify(fs.writeFile);
+  await writeFile(outputFile, response.audioContent, 'binary');
+  console.log(`Audio content written to file: ${outputFile}`);
   // [END tts_synthesize_text]
 }
 
-function synthesizeSsml(ssml, outputFile) {
+async function synthesizeSsml(ssml, outputFile) {
   // [START tts_synthesize_ssml]
   const textToSpeech = require('@google-cloud/text-to-speech');
   const fs = require('fs');
+  const util = require('util');
 
   const client = new textToSpeech.TextToSpeechClient();
 
@@ -70,27 +60,18 @@ function synthesizeSsml(ssml, outputFile) {
     audioConfig: {audioEncoding: 'MP3'},
   };
 
-  client.synthesizeSpeech(request, (err, response) => {
-    if (err) {
-      console.error('ERROR:', err);
-      return;
-    }
-
-    fs.writeFile(outputFile, response.audioContent, 'binary', err => {
-      if (err) {
-        console.error('ERROR:', err);
-        return;
-      }
-      console.log(`Audio content written to file: ${outputFile}`);
-    });
-  });
+  const [response] = await client.synthesizeSpeech(request);
+  const writeFile = util.promisify(fs.writeFile);
+  await writeFile(outputFile, response.audioContent, 'binary');
+  console.log(`Audio content written to file: ${outputFile}`);
   // [END tts_synthesize_ssml]
 }
 
-function synthesizeTextFile(textFile, outputFile) {
+async function synthesizeTextFile(textFile, outputFile) {
   // [START tts_synthesize_text_file]
   const textToSpeech = require('@google-cloud/text-to-speech');
   const fs = require('fs');
+  const util = require('util');
 
   const client = new textToSpeech.TextToSpeechClient();
 
@@ -106,27 +87,18 @@ function synthesizeTextFile(textFile, outputFile) {
     audioConfig: {audioEncoding: 'MP3'},
   };
 
-  client.synthesizeSpeech(request, (err, response) => {
-    if (err) {
-      console.error('ERROR:', err);
-      return;
-    }
-
-    fs.writeFile(outputFile, response.audioContent, 'binary', err => {
-      if (err) {
-        console.error('ERROR:', err);
-        return;
-      }
-      console.log(`Audio content written to file: ${outputFile}`);
-    });
-  });
+  const [response] = await client.synthesizeSpeech(request);
+  const writeFile = util.promisify(fs.writeFile);
+  await writeFile(outputFile, response.audioContent, 'binary');
+  console.log(`Audio content written to file: ${outputFile}`);
   // [END tts_synthesize_text_file]
 }
 
-function synthesizeSsmlFile(ssmlFile, outputFile) {
+async function synthesizeSsmlFile(ssmlFile, outputFile) {
   // [START tts_synthesize_ssml_file]
   const textToSpeech = require('@google-cloud/text-to-speech');
   const fs = require('fs');
+  const util = require('util');
 
   const client = new textToSpeech.TextToSpeechClient();
 
@@ -142,60 +114,54 @@ function synthesizeSsmlFile(ssmlFile, outputFile) {
     audioConfig: {audioEncoding: 'MP3'},
   };
 
-  client.synthesizeSpeech(request, (err, response) => {
-    if (err) {
-      console.error('ERROR:', err);
-      return;
-    }
-
-    fs.writeFile(outputFile, response.audioContent, 'binary', err => {
-      if (err) {
-        console.error('ERROR:', err);
-        return;
-      }
-      console.log(`Audio content written to file: ${outputFile}`);
-    });
-  });
+  const [response] = await client.synthesizeSpeech(request);
+  const writeFile = util.promisify(fs.writeFile);
+  await writeFile(outputFile, response.audioContent, 'binary');
+  console.log(`Audio content written to file: ${outputFile}`);
   // [END tts_synthesize_ssml_file]
 }
 
+async function main() {
 require(`yargs`) // eslint-disable-line
-  .demand(1)
-  .command(`text <text>`, `Synthesizes audio file from text`, {}, opts =>
-    synthesizeText(opts.text, opts.outputFile)
-  )
-  .command(`ssml <ssml>`, `Synthesizes audio file from SSML`, {}, opts =>
-    synthesizeSsml(opts.ssml, opts.outputFile)
-  )
-  .command(
-    `text-file <textFile>`,
-    `Synthesizes audio file from text in a file`,
-    {},
-    opts => synthesizeTextFile(opts.textFile, opts.outputFile)
-  )
-  .command(
-    `ssml-file <ssmlFile>`,
-    `Synthesizes audio file from SSML in a file`,
-    {},
-    opts => synthesizeSsmlFile(opts.ssmlFile, opts.outputFile)
-  )
-  .options({
-    outputFile: {
-      alias: 'o',
-      default: 'output.mp3',
-      global: true,
-      requiresArg: true,
-      type: 'string',
-    },
-  })
-  .example(`node $0 text "hello" -o hello.mp3`)
-  .example(`node $0 ssml "<speak>Hello there.</speak>" -o hello.mp3`)
-  .example(`node $0 text-file resources/hello.txt -o output.mp3`)
-  .example(`node $0 ssml-file resources/hello.ssml -o output.mp3`)
-  .wrap(120)
-  .recommendCommands()
-  .epilogue(
-    `For more information, see https://cloud.google.com/text-to-speech/docs`
-  )
-  .help()
-  .strict().argv;
+    .demand(1)
+    .command(`text <text>`, `Synthesizes audio file from text`, {}, opts =>
+      synthesizeText(opts.text, opts.outputFile)
+    )
+    .command(`ssml <ssml>`, `Synthesizes audio file from SSML`, {}, opts =>
+      synthesizeSsml(opts.ssml, opts.outputFile)
+    )
+    .command(
+      `text-file <textFile>`,
+      `Synthesizes audio file from text in a file`,
+      {},
+      opts => synthesizeTextFile(opts.textFile, opts.outputFile)
+    )
+    .command(
+      `ssml-file <ssmlFile>`,
+      `Synthesizes audio file from SSML in a file`,
+      {},
+      opts => synthesizeSsmlFile(opts.ssmlFile, opts.outputFile)
+    )
+    .options({
+      outputFile: {
+        alias: 'o',
+        default: 'output.mp3',
+        global: true,
+        requiresArg: true,
+        type: 'string',
+      },
+    })
+    .example(`node $0 text "hello" -o hello.mp3`)
+    .example(`node $0 ssml "<speak>Hello there.</speak>" -o hello.mp3`)
+    .example(`node $0 text-file resources/hello.txt -o output.mp3`)
+    .example(`node $0 ssml-file resources/hello.ssml -o output.mp3`)
+    .wrap(120)
+    .recommendCommands()
+    .epilogue(
+      `For more information, see https://cloud.google.com/text-to-speech/docs`
+    )
+    .help()
+    .strict().argv;
+}
+
+main().catch(console.error);