Voice mode regression: transcription broken in 2.1.81-2.1.83 (works in 2.1.80)

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report (please file separate reports for different bugs)
• [x] I am using the latest version of Claude Code

What's Wrong?

Voice mode activates ("listening.." indicator appears, colored block cursor animates across the screen), but no transcribed text ever appears in the input field. When Space is released, the indicator disappears and the prompt is empty. No error messages are shown.

This is a regression — voice transcription works correctly on 2.1.80 but is broken on 2.1.81, 2.1.82, and 2.1.83.

Key evidence:

• Claude Desktop app voice mode works perfectly on the same machine, same microphone, same Anthropic account — confirming the mic, audio pipeline, and server-side transcription service are all functional.
• Rolling back to 2.1.80 via ln -sf ~/.local/share/claude/versions/2.1.80 ~/.local/bin/claude immediately restores working voice transcription in the CLI.
• The visual behavior differs between working and broken versions: in 2.1.80 the cursor stays at the start of the input and transcribed text populates progressively. In 2.1.83 the cursor moves across the screen but no text appears.

What Should Happen?

When holding Space in voice mode, audio should be captured and transcribed text should progressively appear in the input field, as it does in 2.1.80.

Error Messages/Logs

No visible errors. CLAUDE_DEBUG=1 claude 2>/tmp/debug.log produces an empty log file for voice-related events.

Additional finding: rec (sox) reports can't set sample rate 16000; using 48000 — if the native audio path is broken and falls back to rec, the sample rate mismatch could explain why the server returns no transcription. However, this is likely a secondary issue since native audio should be used on macOS.

Steps to Reproduce

1. Install Claude Code 2.1.83 (fresh install via curl -fsSL https://claude.ai/install.sh | bash)
2. Run claude in Terminal.app
3. /voice to disable, /voice to re-enable (required due to #36748)
4. Hold Space and speak
5. Observe: "listening.." appears, cursor animates, but no text is transcribed
6. Release Space — input field is empty

Workaround

Roll back to 2.1.80:

ln -sf ~/.local/share/claude/versions/2.1.80 ~/.local/bin/claude

Claude Model

Claude Opus 4.6

Is this a regression?

Yes

Last Working Version

2.1.80

Claude Code Version

2.1.83

Platform

Claude.ai (OAuth)

Operating System

macOS (Darwin 25.1.0, arm64)

Terminal/Shell

Terminal.app (zsh)

Additional Information

• Authentication: claudeAiOauth
• sox installed via Homebrew (14.4.2_6)
• rec sample rate warning: can't set sample rate 16000; using 48000
• Microphone permissions confirmed for Terminal.app in System Settings > Privacy & Security > Microphone
• No third-party voice/audio tools interfering (superwhisper quit, third-party voice-mode MCP removed)
• Related issues: #36748 (voice not initializing on startup), #33383 (voice mode not functioning)