Android 10 and higher include a CTS Verifier test for Pro Audio compliance, which tests round-trip audio latency. Unlike many CTS Verifier tests that run automatically, the Pro Audio test requires human intervention to select and connect an appropriate peripheral to the device under test (DUT).
Selecting an audio peripheral
An appropriate peripheral is one that has sufficient playback and record functionality and can directly connect to the DUT to accurately measure round-trip latency through the audio path. Because analog, digital, and Bluetooth headsets can't be directly connected to device outputs and inputs, these peripherals are not appropriate peripherals and can't used for the Pro Audio test.
Acceptable peripherals include the following:
USB audio interface. This peripheral can be any USB audio interface that can have its outputs and inputs directly connected to the device with patch cables. All mandated USB audio interfaces required by the USB Audio Peripherals Play or Record CTS Verifier test meet this peripheral requirement.
Figure 1. Example USB audio interface
When using a USB interface with input level controls, you might need to adjust the controls to a nonzero value; this is typically done when calibrating the signal level. If the audio interface passed the USB Audio Peripheral Record test, the input level setting used in that test should work in the Pro Audio test as well.
Loopback plug, USB-C digital-to-analog adapter
Figure 2. Loopback plug with USB-C digital-to-analog adapter
Loopback plug, 3.5 mm analog jack
Figure 3. Loopback plug with 3.5 mm analog jack
Running the Pro Audio test
To run the CTS Verifier Pro Audio test:
Directly connect an appropriate audio peripheral to the DUT.
On the device, launch the CTS Verifier app.
In the list of tests, select Pro Audio Test.
In the Pro Audio Test module, verify that the test prerequisites are met (values are true or N/A), then tap Round-Trip Test.
Figure 4. CTS Verifier, Pro Audio test module
Use the returned values to verify that all CDD Pro Audio requirements have been met.
For latency criteria, see Professional Audio.
To get a sufficient Confidence value, you might need to run the test more than once.
Tap to indicate compliance.