fix: AWSTranscribeSTTService always set to us-east-1

CHANGELOG.md

@@ -15,6 +15,11 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 - The `noise_gate_enable` parameter in `AICFilter` is deprecated and no longer has any effect. Noise gating is now handled automatically by the AIC VAD system. Use `AICFilter.create_vad_analyzer()` for VAD functionality instead.
 
+### Fixed
+
+- Fixed an issue in `AWSTranscribeSTTService` where the `region` arg was
+  always set to `us-east-1` when providing an AWS_REGION env var.
+
 ## [0.0.96] - 2025-11-26 🦃 "Happy Thanksgiving!" 🦃
 
 ### Added
@@ -293,7 +298,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ### Fixed
 
 - Fixed an issue in `AWSBedrockLLMService` where the `aws_region` arg was
-  always set to `us-east-1`.
+  always set to `us-east-1` when providing an AWS_REGION env var.
 
 - Fixed an issue with `DeepgramFluxSTTService` where it sometimes failed to reconnect.
 

src/pipecat/services/aws/stt.py

@@ -58,7 +58,7 @@ class AWSTranscribeSTTService(STTService):
         api_key: Optional[str] = None,
         aws_access_key_id: Optional[str] = None,
         aws_session_token: Optional[str] = None,
-        region: Optional[str] = "us-east-1",
+        region: Optional[str] = None,
         sample_rate: int = 16000,
         language: Language = Language.EN,
         **kwargs,
@@ -69,7 +69,7 @@ class AWSTranscribeSTTService(STTService):
             api_key: AWS secret access key. If None, uses AWS_SECRET_ACCESS_KEY environment variable.
             aws_access_key_id: AWS access key ID. If None, uses AWS_ACCESS_KEY_ID environment variable.
             aws_session_token: AWS session token for temporary credentials. If None, uses AWS_SESSION_TOKEN environment variable.
-            region: AWS region for the service. Defaults to "us-east-1".
+            region: AWS region for the service.
             sample_rate: Audio sample rate in Hz. Must be 8000 or 16000. Defaults to 16000.
             language: Language for transcription. Defaults to English.
             **kwargs: Additional arguments passed to parent STTService class.