# 2nd Opinion

> Free desktop app that checks audiobook files against Audible/ACX technical specs — peak, RMS, sample rate, and head/tail silence.

Source: https://selfpublishingdirectory.com/audiobook/2nd-opinion
Website: https://stevenjaycohen.com/2ndopinion/
Category: Audiobook Production (https://selfpublishingdirectory.com/audiobook)
Pricing: free — $0
AI-powered: no
Tags: free, technical-qc, acx, audible, desktop-app, rms, peak-level, open-tool
Last verified: 2026-07-01
Best For: Self-narrating authors and narrators who want a free pre-submission technical spec check on Mac, Windows, or Linux
Narration Type: human, ai
Royalty Rate: 
Service Type: proofing-qc

2nd Opinion, by narrator and developer Steven Jay Cohen, is a free cross-platform desktop app that scans finished audiobook files against Audible's direct-ingestion technical specs (stricter than ACX's) so you catch spec violations before you submit. Version 7.0.1 shipped in July 2025 and the tool is actively maintained.

- **Best for:** Self-narrating authors and narrators who want a free, repeatable technical QC pass before uploading to Audible or ACX
- **Key features:** Checks peak level (default ≤ -3.0 dB), average RMS (-18 to -23 dB), consistent channel count and sample rate (44.1k default), head silence (½–¾ sec), tail silence (2½–5 sec), and retail-sample length; thresholds are customizable
- **Platforms:** macOS (Apple Silicon and Intel), Windows, and Linux
- **Pricing:** Completely free; the developer accepts optional donations
- **Limitation:** Technical audio analysis only — it does not check manuscript accuracy or narration performance, so pair it with a human proof-listener for content errors