/voice mode: audio levels visible but no transcription returned

Description

Voice mode (/voice) shows audio levels in the terminal (microphone is working) but no transcribed text is ever returned after releasing Space. No error message is shown.

Environment

• Claude Code version: 2.1.83 (also tested on 2.1.81 - same behaviour)
• OS: macOS (Darwin 25.4.0, Apple Silicon)
• Terminals tested: Warp, Terminal.app - same result in both
• Auth: Claude.ai login (not API key)
• sox: Installed via Homebrew, confirmed working independently (sox -d -t wav records successfully)
• Microphone: Confirmed working, terminal has mic permissions granted

Steps to reproduce

1. Run claude
2. Run /voice (shows "Voice mode enabled. Hold Space to record.")
3. Hold Space - audio level indicator appears and responds to voice input
4. Release Space
5. No transcription appears. Input returns to normal with no error.

Expected behaviour

Transcribed text should appear in the input after releasing Space.

Possibly related

• #38819
• #38804