diff --git a/lib/synth-audio.js b/lib/synth-audio.js
index ac239c7..b05836f 100644
--- a/lib/synth-audio.js
+++ b/lib/synth-audio.js
@@ -411,6 +411,8 @@ const synthMicrosoft = async(logger, {
       let params = '';
       params += `{api_key=${apiKey}`;
       params += `,language=${language}`;
+      params += ',vendor=microsoft';
+      params += `,voice=${voice}`;
       if (region) params += `,region=${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}`;