---
title: "APTO Loudness Control"
slug: "apto-loudness-control"
updated: 2024-11-06T09:30:51Z
published: 2024-11-06T09:30:51Z
canonical: "docs.telosalliance.com/apto-loudness-control"
---

> ## Documentation Index
> Fetch the complete documentation index at: https://docs.telosalliance.com/llms.txt
> Use this file to discover all available pages before exploring further.

# APTO Loudness Control

## APTO® Loudness Control

Linear Acoustic APTO® is a state-of-the-art, adaptive loudness processing algorithm that enhances the listening experience, improves dialog intelligibility, and prevents listener annoyance - all without audibly affecting the original sound quality and creative intent.

APTO delivers audio that is fully compliant with various television broadcast regulatory loudness standards including EBU R128, ATSC A/85, FreeTV OP59, ARIB TR-B32, and AGCOM 219/09/CSP as well as the AES-TD1006 streaming standard.

Key controls are included in the APTO window. The ability to create, modify, and store different APTO Profiles is found on the Systems Page. <<FUTURE LINK>>

![Figure 1 - APTO loudness control](https://cdn.document360.io/57e3cd80-d493-453c-9672-ad1b043dadc3/Images/Documentation/image(49)(2)(1)(1)(1)(1)(1)(1).png?sv=2026-02-06&spr=https&st=2026-11-11T01%3A39%3A11Z&se=2026-11-11T02%3A39%3A11Z&sr=c&sp=r&sig=VSLINMDbFdOzmuRD4lqNByugKbxSnGVCrkltfBoIKjE%3D)

Figure 1 - APTO loudness control

### Source

Each Audio Input Group has an individual APTO processor available to it. The Source field is automatically populated and matches the Input Sources as defined at the top of the page.

### Profile

APTO is largely based on presets called Profiles which are selected and recalled in the Profile dropdown. Profiles may be created or modified in the APTO Profile editor section of the System page. <<FUTURE LINK>>

### Target Level

This is the average loudness level to which APTO will process the audio. The word “average” is important here, as maintaining the creative dynamic range that the program producer intended is important and enhances a viewer's expereince.

The Target Level is adjustable in 0.1 dB (LUFS) increments.

### Adaptation

The Adaptation control adjusts the amount of real-time processing applied to the audio versus using metadata control.

### Link

The Link control enables two or more APTO processors to be linked together and track each other as they control loudness. This function is analogous to the link control on standard compressors or on channels in a digital mixing console.