Voice: Add language configuration for speech-to-text transcription

Feature Request

The voice feature currently appears to default to English for speech-to-text transcription. There is no way to configure the transcription language, which makes it difficult to use for non-English speakers.

Problem

When speaking German (or other non-English languages) into the microphone, the transcription does not recognize the language correctly. It seems to only work reliably with English input.

Proposed Solution

Add a configurable language setting for voice transcription. Options could include:

1. Auto-detection (preferred): Automatically detect the spoken language (Whisper supports this natively)
2. Explicit setting: Allow users to set a preferred transcription language, e.g.:

• Environment variable: CLAUDE_VOICE_LANGUAGE=de
• Or in settings.json: "voiceLanguage": "de"
• Or support a list for multilingual users: "voiceLanguages": ["en", "de"]

Use Case

I'm a German speaker using Claude Code daily. I frequently switch between English and German when communicating with Claude. The voice feature would be much more useful if it could handle both languages.

Environment

• Platform: Linux (WSL2)
• Claude Code version: 2.x