diff --git a/packages/text-to-speech/src/index.ts b/packages/text-to-speech/src/index.ts
index 7bd73a448..efd17a700 100644
--- a/packages/text-to-speech/src/index.ts
+++ b/packages/text-to-speech/src/index.ts
@@ -279,16 +279,50 @@ export const textToSpeechStreamingHandler = Sentry.GCPFunction.wrapHttpFunction(
         return
       }
       console.log('Cache miss')
-      // synthesize text to speech if cache miss
+
+      const bucket = process.env.GCS_UPLOAD_BUCKET
+      if (!bucket) {
+        throw new Error('GCS_UPLOAD_BUCKET not set')
+      }
+
+      // audio file to be saved in GCS
+      const audioFileName = `speech/${cacheKey}.mp3`
+      const speechMarksFileName = `speech/${cacheKey}.json`
+      const audioFile = createGCSFile(bucket, audioFileName)
+      const speechMarksFile = createGCSFile(bucket, speechMarksFileName)
+      // check if audio file already exists
+      const [exists] = await audioFile.exists()
+      if (exists) {
+        console.debug('Audio file already exists')
+        const [audioData] = await audioFile.download()
+        const [speechMarksExists] = await speechMarksFile.exists()
+
+        return {
+          audioData,
+          speechMarks: speechMarksExists
+            ? JSON.parse((await speechMarksFile.download()).toString())
+            : [],
+        }
+      }
+
       const input: TextToSpeechInput = {
         ...utteranceInput,
         textType: 'ssml',
         key: cacheKey,
       }
+      // synthesize text to speech if cache miss
       const { audioData, speechMarks } = await synthesizeTextToSpeech(input)
       if (!audioData) {
         return res.status(500).send({ errorCode: 'SYNTHESIZER_ERROR' })
       }
+
+      // upload audio data to GCS
+      await audioFile.save(audioData)
+      // upload speech marks to GCS
+      if (speechMarks.length > 0) {
+        await speechMarksFile.save(JSON.stringify(speechMarks))
+      }
+
       const audioDataString = audioData.toString('hex')
       // save audio data to cache for 24 hours for mainly the newsletters
       await redisClient.set(
diff --git a/packages/text-to-speech/src/realisticTextToSpeech.ts b/packages/text-to-speech/src/realisticTextToSpeech.ts
index 9e6451db0..94a0a9c7a 100644
--- a/packages/text-to-speech/src/realisticTextToSpeech.ts
+++ b/packages/text-to-speech/src/realisticTextToSpeech.ts
@@ -7,7 +7,6 @@ import axios from 'axios'
 import ffmpegPath from '@ffmpeg-installer/ffmpeg'
 import ffmpeg from 'fluent-ffmpeg'
 import { PassThrough } from 'stream'
-import { createGCSFile } from './index'
 
 ffmpeg.setFfmpegPath(ffmpegPath.path)
 
@@ -46,28 +45,6 @@ export class RealisticTextToSpeech implements TextToSpeech {
       throw new Error('PlayHT API credentials not set')
     }
 
-    const bucket = process.env.GCS_UPLOAD_BUCKET
-    if (!bucket) {
-      throw new Error('GCS_UPLOAD_BUCKET not set')
-    }
-
-    // audio file to be saved in GCS
-    const audioFileName = `speech/${input.key}.mp3`
-    const audioFile = createGCSFile(bucket, audioFileName)
-    // check if audio file already exists
-    const [exists] = await audioFile.exists()
-    if (exists) {
-      console.debug('Audio file already exists')
-      const [audioData] = await audioFile.download()
-      return {
-        audioData,
-        speechMarks: [],
-      }
-    }
-
-    const outputStream = audioFile.createWriteStream({
-      resumable: true,
-    }) as PassThrough
     const inputStream = new PassThrough()
 
     const HEADERS = {
@@ -100,8 +77,8 @@ export class RealisticTextToSpeech implements TextToSpeech {
     // timeout after 1 hour
     const timeout = 60 * 60 * 1000
     const startTime = Date.now()
-    let audioData: Buffer | undefined
-    while (!audioData) {
+    let isReady = false
+    while (!isReady) {
       if (Date.now() - startTime > timeout) {
         throw new Error('Timeout when polling the download url')
       }
@@ -117,17 +94,33 @@ export class RealisticTextToSpeech implements TextToSpeech {
 
         // write the audio file to the input stream
         // eslint-disable-next-line @typescript-eslint/no-unsafe-argument
-        audioData = Buffer.from(downloadResponse.data, 'binary')
-        inputStream.end(audioData)
+        inputStream.end(Buffer.from(downloadResponse.data, 'binary'))
+        isReady = true
       } catch (e) {
         // ignore error
         console.debug('checking status of audio file', downloadUrl)
       }
     }
 
+    const outputStream = new PassThrough()
     // transcode the audio file to mp3
     await convertWavToMp3AndUpload(inputStream, outputStream)
 
+    // convert the buffer stream to a buffer
+    const audioData = await new Promise<Buffer>((resolve, reject) => {
+      const chunks: Buffer[] = []
+      outputStream.on('data', (chunk) => {
+        // eslint-disable-next-line @typescript-eslint/no-unsafe-argument
+        chunks.push(chunk)
+      })
+      outputStream.on('end', () => {
+        resolve(Buffer.concat(chunks))
+      })
+      outputStream.on('error', (err) => {
+        reject(err)
+      })
+    })
+
     return {
       audioData,
       speechMarks: [],