Version: 2.0  

Last updated: 2026-09-28

## Overview

This document describes the requirements a ChromeOS Compatible wired headset
meets. This specification is not for WWCB products, nor for a product designed
and certified together with a Chromebook.

A single peripheral type specifies a subset of Audio modules that combine to
make the spec for that peripheral. This mapping is provided in the [Modular spec
matrix](https://developers.google.com/chromeos/peripherals/modules/cc-spec-module-matrix).

The peripheral specification assembles using the text in this document specific
to the peripheral, plus the relevant portions in each of the designated modules.


### 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>

<br />

## Legend

| Product Verb | Development Action |
|---|---|
| "MUST" | Mandatory product requirement |
| "SHOULD" | Optional recommendation |
| "MAY" | Nice to have |

## MINIMUM REQUIREMENTS

### Generic peripheral Specifications

- The peripheral MUST meet the [minimum requirements](https://developers.google.com/chromeos/peripherals/cc-generic-peripheral-v2#minimum-requirements) defined in the Generic peripheral specifications.

## 3.5mm audio connector hardware specifications

### MINIMUM REQUIREMENTS

#### Plug

- Mechanical
  - 4 conductor 3.5mm plug
  - Pinout order
    - CTIA (LRGM) - Recommended
    - OMTP (LRMG) - Optional
- Electrical
  - Ear speaker impedance
    - ≥ 16 Ω
  - Mic equivalent DC resistance
    - ≥ 1000 Ω

#### Buttons

- Only the following buttons are allowed:
  - Play or Pause (Function A)
  - Volume up (Function B)
  - Volume down (Function C)
- The control function equivalent Impedance\* MUST satisfy the requirements in
  the following table:

  | Function | Impedance^[1](https://developers.google.com/chromeos/peripherals/cc-headset-35mm-v2#fn1)^ range |
  |---|---|
  | Play or Pause (Function A) | \[0, 70\] Ω |
  | Volume up (Function B) | \[210, 290\] Ω |
  | Volume down (Function C) | \[370, 680\] Ω |

### ADDITIONAL REQUIREMENTS

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

#### Buttons

- **\[Mandatory\]** The audio device MUST NOT support the answer or hang up button, the OS does not support it.

## 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.

## Audio Latency

### MINIMUM REQUIREMENTS

- None

### ADDITIONAL REQUIREMENTS

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

#### Latency

- **\[Mandatory\] Output Latency**: Audio playback MUST begin ≤ 500 ms after a user action that initiates playback.

#### Audio-Video (AV) Sync

- **\[Mandatory\] Accuracy**: The audio playback latency report MUST be accurate to real world latency, i.e., ≤ 50 ms.

## Works With Meet Certification

### MINIMUM REQUIREMENTS

There is an existing
[Google Meet hardware peripheral qualification program](https://support.google.com/meethardware/answer/7657004)
covering part of this spec.

Peripherals qualified by the program are exempted from the following
qualification items:

- **Playback Path - Loudness**
- **Capture Path - Output Frequency Response**

### ADDITIONAL REQUIREMENTS

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

- None

<br />

## Revision history

| Date | Version | Notes |
|---|---|---|
| 2026-09-28 | 2.0 | Use minimum and additional requirements format. |
| 2024-06-17 | 1.3.1 | ChromeOS Compatible spec derived. Initial Partner Site Publication. |
| 2022-09-01 | 1.3 | Related WWCB specification v1.3 |
| 2022-06-06 | 1.2 | Related WWCB specification v1.2 |
| 2020-10-14 | 1.1 | Related WWCB specification v1.1 |
| 2020-09-23 | 1.0 | Related WWCB specification created. |

<br />

*** ** * ** ***

1. The equivalent impedance is measured from positive mic terminal to GND
   when button is pressed with 2.2 V mic bias applied through 2.2 kΩ resistor. [↩](https://developers.google.com/chromeos/peripherals/cc-headset-35mm-v2#fnref1)