Transitioning Audio Tests from R&D to the Production Line

Production line audio testing poses many challenges such as noisy environments, harsh operating conditions, high throughput, relative limits, and more. In this article, Steve Temme shares his observations and outlines the main considerations to ensure a successful operation.

- Steve Temme

Your product design is finalized, your prototypes are close to perfect, and your audio product is ready to move to production. But how do you ensure that the product hitting the retail shelves sounds exactly as you intended? Your production line is probably thousands of miles away, with time zone and language complications. Pandemic-related restrictions make it hard to visit to configure, supervise, and train factory personnel. Furthermore, production is often outsourced to a contract manufacturer, adding another layer of complexity to both culture and information transfer.

Every production facility has one priority: to build products that meet the specifications with the greatest efficiency and highest yield possible for optimum profitability. Think about what that means for end-of-line tests. Their goal is to have as many units pass as possible. Tests must be fast to avoid slowing down the production line, and the test environment is generally noisy, often with variable temperature and humidity. The quest for high yields and manufacturing efficiency, along with challenging operating conditions and sometimes poor training, can result in unreliable measurements. When this happens, the only loser is you and your brand's reputation.

I'll never forget being told about a production line operator who increased pass-rate by opening the test box during measurements so that the factory background noise would mask the high-order harmonics to fool the perceptual Rub & Buzz algorithm. This might improve his yield, but it's not so good when these products ship to customers! While this is one of the more outrageous violations of end-of-line test protocol, I have also seen many other questionable measurement practices over the years. In this article, I'll try to de-mystify production tests and look at some simple measures that you can take to ensure a smooth transition.

Production Line Test Considerations