Version: 2.0  

Last updated: 2026-09-28

## Overview

This specification module outlines the audio quality requirements for audio
peripherals.


### Minimum and Additional Requirements

This specification document is divided into two sections:

1. **Minimum** requirements describe the criteria for a peripheral category to be compatible.
2. **Additional** requirements describe the criteria for certification.

Use these navigation buttons to show only the minimum or both the minimum
and additional specification, respectively.
<button value="min">Minimum</button> <button value="add" default="">Minimum and Additional</button>

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## Audio Quality

### MINIMUM REQUIREMENTS

#### Capture Path - Mute

- If there is any interface for users to mute the audio device, it MUST:
  - Maintain the mute state in a way that is not affected by:
    - Opening and closing the device.
    - Switching to another input device.

### ADDITIONAL REQUIREMENTS

Along with the **Minimum** requirements, a peripheral MUST meet the following
requirements to achieve certification:

#### Playback Path - Loudness

- **\[Mandatory\]** The device MUST comply with EN50332 standards.

#### Capture Path - Mute

- **\[Mandatory\]** If there is any interface for users to mute the audio device, it MUST:
  - Mute the device such that all recorded samples are zeros or within the range of \\((level_{max} - level_{min}) \\le 0.0028 \\text{ dBFS}\\).
    - If the device cannot meet the requirements, then the device SHOULD have a button to mute.
    - The mute button on the device SHOULD trigger the system mute (mic).
    - The mute button SHOULD trigger the system mute (mic) through the Telephony, or the Consumer interface can be waived.
- **\[Mandatory\]** If the user presses the mute button on the device or OS, the mute state MUST change.
- **\[Mandatory\]** If the device synchronizes the MUTE state with the OS, then the mute state indicator (e.g., LED) on the device MUST change.

#### Capture Path - Output Frequency Response

- **\[Mandatory\]** The device MUST be fully functional using the factory default frequency response and gain settings without any manual adjustment of the capture gain on OS.
- **\[Mandatory\]** The following table specifies the computed average RMS
  dBFS level output under signal level 94 dBSPL.

  | Device type | Output level range versus sine tone frequency |||
  | Device type | 1 kHz | 4 kHz | 7 kHz |
  |---|---|---|---|
  | Bluetooth and USB | \[-15, -5\] dBFS | 1kHz value ±5 dB | 1kHz value ±5 dB |
  | 3.5 mm wired | \[-23, 0\] dBFS | \[-23, 0\] dBFS | \[-23, 0\] dBFS |

**Note:** In Bluetooth and USB devices, the response around the 4 kHz and 7 kHz
tones is given relative to the response at 1 kHz.

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## Revision history

| Date | Version | Notes |
|---|---|---|
| 2026-09-28 | 2.0 | Update for ChromeOS Compatible specification. |
| 2026-03-03 | 1.3.2 | Formatting update. |
| 2024-06-14 | 1.3.1 | Change formatting around dBFS and kHz. Publish to partner site. |
| 2024-05-07 | 1.3 | Change some format and wording in the doc. |
| 2023-05-10 | 1.2 | Add Just Work requirement. |
| 2023-03-09 | 1.1 | Add different requirement for 3.5mm Output Frequency Response. |
| 2022-12-19 | 1.0 | Initial version. |

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