Voice Clarity Causality Test
Test description
For Voice Clarity echo control to operate properly, the system needs to be causal. In other words, after timestamp alignment, each microphone signal must have positive delay with respect to each speaker loopback signal. This test is to verify the causality of the system, i.e., that the QPC (Query Performance Counter) timestamps and buffers are consistent with the speaker signals being produced before the corresponding measurement at the microphones.
Warning
This test requirement must be satisfied for all speaker-microphone pairs.
Test details
| Specifications |
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| Expected run time (in minutes) | 1 |
| Category | Development |
| Timeout (in minutes) | 5 |
| Requires reboot | false |
| Requires special configuration | false |
| Type | automatic |
Test steps
- Generate a stimulus containing a logarithmic sine sweep in one loudspeaker channel and silence in the remaining channels.
- Render (default mode) the stimulus with a fixed speaker gain and record (raw mode) with a fixed microphone gain.
- Align the speaker and the microphone signals using the QPC timestamps.
- Calculate the delay of each microphone signal with respect to the speaker signal in the loopback channel. The delay is computed via cross-correlation.
- Repeat steps above for each loudspeaker channel.
Pass/Fail criteria
Each microphone signal must have positive delay with respect to each speaker loopback signal.
Troubleshooting
- Verify that capture and render processing do not introduce excessive latency.
- Verify that capture and render timestamps are accurate and share a common time base.
If your failure mode is not included on this list, search the error code in MSDN.
For generic troubleshooting of HLK test failures, see Troubleshooting Windows HLK Test Failures and Troubleshooting System Fundamentals Testing.
More Information
Parameters
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Additional Documentation
Tests in this feature area might have additional documentation, including prerequisites, setup, and troubleshooting information, that can be found in the following topic(s): - Device.Audio additional documentation and System.Fundamentals additional documentation.