Why a well-edited episode still jumps in volume

An episode can sound great on headphones and still send your hand to the knob the moment you play it in the car. That doesn't mean the editor did a bad job. There are simply two different volume problems, and usually only one of them gets solved.

The level of an episode

The first problem is that every episode arrives at a different level. One show was recorded loud, another quiet, and if you listen to a few episodes in a row you don't want to readjust the volume every time a new one starts.

There's a familiar fix for that, called normalisation. You measure the episode's average level and move the whole thing up or down until it hits a fixed target. Many editors do this before they upload an episode. After normalisation you no longer jump from a very quiet episode to a very loud one.

The level of a conversation

The second problem lives inside the episode. A podcast with two people has two voices, and each was recorded differently: on a different microphone, at a different distance from it, in a different room, and sometimes over a remote line.

Normalisation doesn't touch any of this. It moves the whole episode together, so the gap between host and guest comes out of normalisation exactly as it went in. If the guest was quieter than the host before, they're quieter after too. It's just that the episode as a whole is now at the right level. You turn it up when the guest answers, and turn it down again at the host's next sentence, exactly as before.

Closing that gap means handling each voice on its own. You can do it in the edit, track by track, but not every episode gets that treatment. The average is right and the episode sounds good, but the conversation still rises and falls.

Why you notice it in the car

At home, on headphones, there is no noise competing with the quiet voice, so it comes through fairly clearly.

In the car there's constant noise from the engine, the tyres and the wind. To hear the quiet voice over it you turn it up, and when the loud voice comes back it's much louder than it needs to be. A gap that was mildly annoying at home becomes, on the road, a reason to touch the knob every few minutes.

What happens to the producer's file

Nothing. Levelling happens on the listener's phone while the episode plays, and the file on the producer's server stays as it is. Someone listening in another app hears the original episode, and someone listening in LevelCast hears it levelled. The download is counted on the producer's side, as with any other player.

What you can do as a listener

Not much. You can pick a compromise volume and strain a little whenever the guest talks, or you can keep your hand near the knob. Both work, but neither is pleasant on a long drive.

You can also let the player do what the edit didn't, which is what LevelCast does. It listens to the episode as it plays and evens out the speakers on the phone, in real time. The quiet voice comes up, the loud one is held back, and the level of the episode as a whole doesn't drop along the way. There are three strengths, off, normal and strong, and strong is worth trying in a noisy car.

You can check how it sounds in the demo, and how it's built is explained on the how-it-works page.