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High-definition audio was initially developed to be a differentiator between the levels of quality available in headphones in the marketplace. Because there was not a specific benchmark set to define HD audio, the term has evolved to more of a marketing expression than a technical specifications.

Through scientific study, we’ve put together a team of experts to benchmark what it means to be HD quality audio. To help consumers discern what is quality HD audio and what isn’t, we developed an HD Quality UL Mark. Having the UL HD Quality Mark on your audio equipment shows consumers that your claims of having HD quality are scientifically verified and not just a marketing ploy.

To help differentiate what is quality HD audio and what isn’t, we developed an HD Quality UL Mark.

What Type of Testing Will You Do in the Audio Laboratory?

UL will verify claims of subsonic and ultrasonic (HD audio) performance by authentication and evaluation of quality measures such as frequency response, THD, signal-to-noise ratio, phase, crosstalk, and sample rate and bit-depth capability.

How Will We Conduct the Test?

To test for HD quality, we conduct what we call an objective test. During this test, we place headphones on a Head and Torso Simulator. The head and torso system then measures the frequencies produced by the product.

For the subjective test, a panel of 30 consumers and 5 industry professionals will be chosen to participate. Each participant is required to complete a questionnaire of about 40-50 questions while listening to different types of music. Then, we create a report for the manufacturer to show findings and what people think about the sound quality of the headphones.