Factory Audio Test Needs Objective Signals Before Human Listening

A worker saying a unit sounds fine cannot be the only acoustic acceptance criterion.

The lab result behind Factory Audio Test Needs Objective Signals Before Human Listening changed the implementation more than the first hypothesis did. LOUP speaker and microphone validation needs repeatable electrical or acoustic stimuli that can catch wiring, gain and gross response failures before subjective inspection.

A fixture can play a known signal, capture microphone response, verify codec detection, check amplifier enable and compare level against broad limits. Human listening remains useful for artifacts the fixture does not model, but it should sit on top of objective checks.

Reversibility stayed part of the experiment: preserve the previous artifact, make the change, then prove the new path before promoting it. Evidence marker: factory-audio-test.

Factory tests should be fast, bounded and repeatable. Subjective quality control works better after obvious electrical failures are already removed. Preserving that distinction is what lets the project increase complexity without losing the ability to explain a regression.

Project evidence

LOUP engineering marker: factory-audio-test. This note records the design or debugging lesson without publishing device credentials, private keys, customer data or manufacturing secrets.