Amazon Transcribe is an automatic speech recognition (ASR) service that makes it easy for you to add a speech-to-text capability to your applications. Up until now, Amazon Transcribe used Amazon S3-SSE to encrypt transcripts. Starting today, you can use your own encryption keys from the AWS Key Management Service (KMS) to encrypt transcripts placed in your S3 bucket. Doing so provides users added flexibility and control over how to secure their output transcripts. For those who prefer to continue using the default S3-SSE encryption method, that will still be an available option.
from Recent Announcements https://aws.amazon.com/about-aws/whats-new/2019/09/amazon-transcribe-supports-aws-kms-encryption/