This page covers the general instructions, required test equipment, and test suite mapping for running the audio tests in CTS Verifier (CTS-V).
General instructions
The following procedures apply to all tests:
- Test setup: For each test, you need a device under test (DUT), which is the Android-powered device you're testing, and an installed version of CTS-V associated with the Android OS version running on the DUT. For more general information about CTS-V requirements and setup, see Using CTS Verifier.
Test information: To run an audio CTS-V test, launch the CTS-V app, and then select the preferred test from the CTS Verifier test list. Opening a test for the first time displays the info panel for that test, which contains the following information:
- Test purpose
- Test protocol
- Required peripherals
- Reference to the relevant CDD section
To close the info panel, tap OK. To view the info panel at any time during testing, tap the ? button.
Test runs: Use the test-specific instructions in this section to run each audio test.
- When the test passes, the checkmark Pass button is enabled. Record a passed test by tapping this button. Some tests also display the message PASS near the bottom row of buttons.
- Record failed tests by tapping the X button.
Optional and feature-gated tests: When a DUT doesn't declare a required hardware port or system feature for a test (or specific test route), CTS-V displays a "Skippable or Non-Mandatory" message (or skips the unsupported route) and automatically enables the Pass button.
Many CTS-V audio tests are self-contained and provide full instructions directly in the app (tap the ? button). The guides in this section cover tests that require external hardware setups, calibration panels, or peripheral configurations.
Test equipment and common panels
CTS-V audio tests use the following test equipment and shared configuration panels:
- Standalone DUT (built-in speaker and microphone): Uses the device's internal speakers and microphones in a quiet environment (no external hardware required).
- 3.5 mm analog headset: Standard wired 4-conductor, 3.5 mm headset with a microphone and inline media buttons (used for headset plug and key-code detection).
- Audio loopback plug: A 3.5 mm TRRS loopback plug that routes headphone output directly back to the microphone input.
- USB-to-analog headset adapter: Converts a USB digital audio signal to a standard 3.5 mm analog jack (used with a 3.5 mm analog headset or audio loopback plug).
- USB audio interface: An external multi-channel USB audio interface connected with 1/4-inch patch cables (for loopback) and a USB OTG adapter.
- Multichannel USB audio peripherals: A 4-in/4-out USB audio interface (such as Zoom AMS-44 or Focusrite Scarlett 4i4) with Y-splitter or 1/4-inch patch cables for 4-channel input testing, and a 7.1-channel USB audio adapter (such as Vantec NBA-200U) with a 6-way stereo audio mixer (or 4-channel audio switcher) and 3.5 mm breakout cables for 8-channel output testing.
- MIDI peripherals: A USB MIDI peripheral (with standard 5-pin DIN MIDI loopback cable), a Bluetooth LE (BLE) MIDI device, or a virtual MIDI synth app.
- Auxiliary device: A second calibrated Android-powered device capable of playing and recording near-ultrasound frequencies.
- Head-tracking device: A spatial audio head-tracking headset or motion test rig.
- Shared CTS-V UI panels:
- Audio loopback calibration panel: Used across standalone, 3.5 mm analog, and USB loopback tests to calibrate output and input signal levels before running a test.
- Audio devices panel: Displays connected audio input and output peripherals to verify device discovery and routing capabilities.
Required test equipment by test
The following table lists the test equipment and shared panels used by each documented CTS-V audio test suite:
| Audio test and guide | Standalone (built-in speaker and mic) | 3.5 mm headset | Audio loopback plug | USB-to-analog adapter | USB audio interface | Other equipment | Common panels used |
|---|---|---|---|---|---|---|---|
| Audio data paths tests | Yes (speaker and mic route) | — | Yes (analog jack route) | Yes (USB adapter route) | Yes (USB interface route) | — | Audio loopback calibration, Audio devices |
| Audio frequency tests | — | — | Yes (frequency line) | — | — | External speaker, USB reference mic, SPL meter | — |
| Audio workload test | Yes | — | — | — | — | — | — |
| Basic audio system functionality tests | — | Yes | Optional | Optional | Optional | — | — |
| Head tracking latency test | — | — | — | — | — | Head-tracking device or test rig | — |
| Latency compliance tests | Yes | — | Yes (loopback latency) | Yes (loopback latency) | Yes (loopback latency) | — | Audio loopback calibration, Audio devices |
| MIDI tests | Yes (virtual MIDI) | — | — | — | Yes (with MIDI jacks) | MIDI cable, BLE MIDI device | — |
| Multichannel input and multichannel output tests | — | — | — | — | Yes (4-in and 4-out USB interface) | 7.1 USB audio adapter, 6-way stereo mixer (or 4-channel switcher), Y-splitter cables | Audio loopback calibration, Audio devices |
| Multichannel mixdown test | Yes (mic and speaker route) | — | Yes (analog jack route) | Yes (USB adapter route) | Yes (USB interface route) | — | Audio loopback calibration, Audio devices |
| Near ultrasound tests | Yes | — | — | — | — | Auxiliary Android-powered device | — |
| Pro audio test | Yes | — | — | — | — | — | — |
| USB audio tests | — | Yes (with a USB adapter) | — | Yes | Yes | Patch cables, USB OTG adapter | — |
Audio test index
The following table lists the individual CTS-V audio tests covered in each test guide category and when each test is required:
| Test guide | Individual CTS-V test | When required |
|---|---|---|
| Audio data paths tests | Audio data paths analog jack test | FEATURE_AUDIO_OUTPUT, FEATURE_MICROPHONE, and 3.5 mm analog headset jack |
| Audio data paths speaker and microphone test | FEATURE_AUDIO_OUTPUT and FEATURE_MICROPHONE |
|
| Audio data paths USB test | FEATURE_AUDIO_OUTPUT, FEATURE_MICROPHONE, and USB audio interface or headset support |
|
| Audio frequency tests | Audio frequency line test | FEATURE_AUDIO_OUTPUT, FEATURE_MICROPHONE, and 3.5 mm analog headset jack |
| Audio frequency speaker test | FEATURE_AUDIO_OUTPUT, FEATURE_USB_HOST, and USB reference microphone support |
|
| Audio frequency microphone test | FEATURE_AUDIO_OUTPUT, FEATURE_MICROPHONE, FEATURE_USB_HOST, and USB reference microphone support |
|
| Audio frequency unprocessed test and voice recognition test | FEATURE_MICROPHONE, FEATURE_USB_HOST, and USB reference microphone support (unprocessed also requires PROPERTY_SUPPORT_AUDIO_SOURCE_UNPROCESSED) |
|
| Audio workload test | Audio workload test | FEATURE_AUDIO_OUTPUT and FEATURE_AUDIO_LOW_LATENCY |
| Basic audio system functionality tests | Analog headset audio test | 3.5 mm analog headset jack |
| Input devices notifications test | FEATURE_MICROPHONE, and 3.5 mm analog jack or USB audio support |
|
| Output devices notifications test | FEATURE_AUDIO_OUTPUT, and 3.5 mm analog jack or USB audio support |
|
| Input routing notifications test | FEATURE_MICROPHONE, and 3.5 mm analog jack or USB audio support |
|
| Output routing notifications test | FEATURE_AUDIO_OUTPUT, and 3.5 mm analog jack or USB audio support |
|
| Audio stream disconnect test | FEATURE_AUDIO_OUTPUT, FEATURE_MICROPHONE, and 3.5 mm analog jack or USB audio support |
|
| Head tracking latency test | Head tracking latency test | FEATURE_AUDIO_SPATIAL_HEADTRACKING_LOW_LATENCY |
| Latency compliance tests | Cold start input latency test | FEATURE_MICROPHONE |
| Cold start output latency test | FEATURE_AUDIO_OUTPUT |
|
| Audio tap to tone test | FEATURE_AUDIO_OUTPUT, FEATURE_MICROPHONE, and FEATURE_TOUCHSCREEN |
|
| Audio loopback latency test | FEATURE_AUDIO_OUTPUT and FEATURE_MICROPHONE (per route: built-in speaker and mic, 3.5 mm jack, or USB audio support) |
|
| MIDI tests | USB MIDI loopback test | FEATURE_MIDI and FEATURE_USB_HOST |
| Virtual MIDI loopback test | FEATURE_MIDI |
|
| Bluetooth MIDI loopback test (Android 16 or higher) | FEATURE_MIDI and BLE support |
|
| Bluetooth MIDI loopback test (Android 15 or lower) | FEATURE_MIDI and BLE support |
|
| Multichannel input and multichannel output tests | Audio data paths USB 4-channel input test | FEATURE_AUDIO_OUTPUT, FEATURE_MICROPHONE, and USB audio interface support |
| Audio data paths USB multichannel test (8-channel output) | FEATURE_AUDIO_OUTPUT, FEATURE_MICROPHONE, and USB audio interface support |
|
| Multichannel mixdown test | Multichannel mixdown test | FEATURE_AUDIO_OUTPUT and FEATURE_MICROPHONE (per route: built-in speaker and mic, 3.5 mm jack, or USB audio support) |
| Near ultrasound tests | Near ultrasound microphone tests | FEATURE_MICROPHONE and PROPERTY_SUPPORT_MIC_NEAR_ULTRASOUND |
| Near ultrasound speaker tests | FEATURE_AUDIO_OUTPUT and PROPERTY_SUPPORT_SPEAKER_NEAR_ULTRASOUND |
|
| Pro audio test | Pro audio test | FEATURE_AUDIO_PRO and FEATURE_USB_HOST |
| USB audio tests | USB audio peripheral attributes test | FEATURE_USB_HOST |
| USB audio peripheral play test | FEATURE_USB_HOST |
|
| USB audio peripheral record (loopback) test | FEATURE_USB_HOST |
|
| USB audio peripheral headset buttons test | FEATURE_USB_HOST |