Working group nears standard for audio levels in PRSS content

A chart created by NPR engineering staff shows the widely varying volume levels of shows distributed via the Public Radio Satellite System.

Members of an NPR working group aiming to standardize levels of audio content delivered via the Public Radio Satellite System believe they have found one possible solution to the problem.

Programs sent to stations through the PRSS vary widely in volume and may detract from the listener’s experience, according to Chris Nelson, NPR’s director of digital strategy. In May, Nelson shared with the NPR Board results of a study in which about 53 percent of the content examined by the working group deviated from standards PRSS recommends for consistent volumes. The group aims to give stations and producers affordable best practices and resources to help solve the problem.

At a meeting Thursday of NPR’s board, Nelson told board members that the working group has consulted with producers and engineers about the issue and conducted a survey to learn how the problem affects stations that use and contribute PRSS content. Out of 255 respondents, 86 percent reported problems with inconsistent audio levels, but fewer than one in five stations had tools to help fix them.

Eighty-one percent of stations reported that they weren’t monitoring audio levels for consistency among programs. “Many people told us they just lived with it,” Nelson said. Most respondents expressed support for efforts to standardize the volume of PRSS content.

Working group members believe that one solution may lie in promoting the use of loudness meters, which offer more precision by measuring audio levels numerically. Most shows are now mixed using peak meters, which are less exact.

As an experiment, the working group applied loudness meters to NPR’s Morning Edition and found that the show’s audio levels were more consistent, whereas use of peak meters resulted in widely varying levels. The loudness meters were set at -24 LUFS, an international standard for measuring loudness. (For lots more about this, read this commentary by Current contributor Adam Ragusea.)

Using that benchmark would also cause less disruption for joint licensees, Nelson said, since PBS also uses the standard. “It just makes a lot of sense,” he said.

Nelson said he would provide another update at the NPR board’s November meeting.