diff --git a/lib/synth-audio.js b/lib/synth-audio.js
index cb49653..edee6bd 100644
--- a/lib/synth-audio.js
+++ b/lib/synth-audio.js
@@ -141,7 +141,7 @@ async function synthAudio(client, logger, stats, { account_sid,
   let filePath;
   if (['nuance', 'nvidia'].includes(vendor) ||
     (
-      process.env.JAMBONES_TTS_TRIM_SILENCE &&
+      (process.env.JAMBONES_TTS_TRIM_SILENCE || !process.env.JAMBONES_DISABLE_TTS_STREAMING) &&
       ['microsoft', 'azure'].includes(vendor)
     ) ||
     (
@@ -414,6 +414,7 @@ const synthMicrosoft = async(logger, {
       params += `,language=${language}`;
       params += ',vendor=microsoft';
       params += `,voice=${voice}`;
+      params += ',write_cache_file=1';
       if (region) params += `,region=${region}`;
       if (custom_tts_endpoint) params += `,endpointId=${custom_tts_endpoint}`;
       if (process.env.JAMBONES_HTTP_PROXY_IP) params += `,http_proxy_ip=${process.env.JAMBONES_HTTP_PROXY_IP}`;
diff --git a/package-lock.json b/package-lock.json
index 5ae7bdc..6bb28a6 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1,12 +1,12 @@
 {
   "name": "@jambonz/speech-utils",
-  "version": "0.0.45",
+  "version": "0.0.47",
   "lockfileVersion": 2,
   "requires": true,
   "packages": {
     "": {
       "name": "@jambonz/speech-utils",
-      "version": "0.0.45",
+      "version": "0.0.47",
       "license": "MIT",
       "dependencies": {
         "@aws-sdk/client-polly": "^3.496.0",
diff --git a/package.json b/package.json
index 0d3523c..7dbc082 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@jambonz/speech-utils",
-  "version": "0.0.45",
+  "version": "0.0.47",
   "description": "TTS-related speech utilities for jambonz",
   "main": "index.js",
   "author": "Dave Horton",