At a certain LA station we did some tests of having both staff and listener listen while we turned encoding off and on randomly. Nobody got close to a 50% of the instances right, and most of the times when people "detected" activation on and off were not actual points of change.
Was this with a modern eCBET encoder, with no Voltair enhancement processing of any form inline?
Most (not all, but most) stations in PPM markets no longer use the first-generation Voltair boxes like the one you heard a long time ago on WMJI. While you were up in Alaska and even now when you're not in a PPM market and haven't been in one for years, technology moved on considerably. First, the addition of the TVC-15 real-time PPM monitor hardware at a lot of stations allowed the encoding to become a lot less obvious, and then the processing manufacturers (mostly Omnia) figured out how to do PPM encoding within their processors, which made it a LOT less obvious.
I still hear some outliers when I travel, but that really harsh metallic flanging stuff you heard years ago is largely a thing of the past. Modern encoding is much friendlier to the ears, especially on FM.
This is not my experience. I keep trying to reconcile the positions of folks like yourself and David on modern-day eCBET being inaudible with what my own ears (and others') continue hearing, because, honestly, on almost every station in Los Angeles
today, I'm still hearing this stuff very clearly, to a degree that makes listening punishing. Yet, judging from your words here, the sound in question should've been banished to the sticks by now, with top markets like Los Angeles having been scrubbed virtually free of it long ago. These two realities just cannot coexist. So as of late, I've begun wondering if the explanation might be that many stations, off the record, simply never stopped running their Voltair boxes even after installing eCBET encoders (or after upgrading to eCBET-enabled audio processors). Check out these two articles I found:
Testing used stations in large or medium markets
www.radioworld.com
Both articles are a decade old, and each claims that Voltair will still improve your ratings with eCBET -- by between 8% and 10% in the second article's case. If boosts that significant were possible then, and if they're still possible today in the current TVC-15, audio processor-integrated eCBET environment you're describing, then what are the odds many stations never decommissioned their Voltairs?
Listen to this brief collage of clips I made off-air from eight Los Angeles stations on August 28, 2024 for another Radio Discussions thread:
https://files.catbox.moe/5junzv.flac
In order, you are hearing KYSR, KPWR, KNX-FM, KOST, KCBS, KLOS, KRTH, and KUSC. Only KPWR and KUSC sound clean to my ears. All of the others sound terrible, with KYSR and KNX-FM being the worst. Today, in 2026, when I scan around the FM dial, everything basically sounds the same to me.
So what could we be hearing here? Is this a sign of Voltair remaining in service as a "secret weapon?" Or is this just the current state of what the industry calls "inaudible?"
Incidentally, here is a
30 minute non-transcoded aircheck I made from KLOS' internet stream during its Yacht Rock weekend last September. The first cut in particular -- Roseanna -- is so audibly affected by the watermarking [enhancement] that the entire song sounds discordant and inharmonic to my ears -- like an old western saloon piano was used in the recording session by Toto. The watermarking is audible to me throughout the entire aircheck, but the way it interacts with certain instruments and/or to certain songs can be absolutely stunning at times, even in modern times.
If there is a list, it would be a radio nerd collated list.
As long as it's collated.
