Setting Up Your Test Environment
The most important aspect of your acoustic test environment is strong sound isolation from external noise sources to ensure reproducible results given identical test parameters. This document will help you create a setup similar to Amazon's. We use an ETSI-compliant audio facility.
- Test room configuration
- Position the DUT and Speech Speaker
- Position the noise speaker
- Connect and testing laptops and speakers
- Position the Echo Dot
Test room configuration
In your test area, the Device Under Test (DUT) should have a clear 180-degree field of view for 2.75 m in front of it. The two speakers used for testing are the exception.
During acoustic testing, the single Speech Speaker is moved to four locations. The Noise Speaker remains in one location. Note that the speaker locations 0.9 m from the DUT (locations 1 & 3) are used only for near-field testing.
Position the DUT and Speech Speaker
- Place the DUT at an elevation representing its typical use case.
- In the "SPL" tab of the Scoresheet, note the elevation of the DUT.
- If there is no particular "front" to the DUT, skip to step 4. If there is a significant "front" orientation for the microphone array of the DUT:
- Aim the front of the DUT toward "Speech Speaker Location 1". (Don't change the orientation of the DUT, regardless of where you move the Speech Speaker for other tests.)
- In the "Information" tab of the Scoresheet, describe this orientation below the table.
- Ensure there is a clear 180-degree field of view in front of the DUT for 2.75 m. No laptops, tables or chairs are allowed inside of that "clear view." (Exception: The Speech Speaker and Noise Speaker can be in this field of view.)
- Elevate the Speech Speaker on its stand so that the center of the speaker cone is at the elevation of the DUT. (This elevation will be used for all Speech Speaker locations.)
- In the "SPL" tab of the Scoresheet, note the elevation of the center of the Speech Speaker cone. If this elevation is different than the elevation of the DUT, mention why below the table in the "SPL" tab.
- For "Location 1" of the Speech Speaker, mark the location as follows:
- Position the base of the Speech Speaker stand so that the face of the speaker cone is the correct distance from the center of the DUT's microphone array.
- Use masking tape to mark the location of the stand. This allows for repeatability in moving the Speech Speaker during tests.
- Likewise, position and mark the stand location for the Speech Speaker in locations 2, 3, and 4. Use the distances and angles shown in the diagrams.
- Return the Speech Speaker to location 1 before further configuration or tests.
Position the noise speaker
The Noise Speaker is placed in one location and orientation, and it remains there from test to test.
- Orient the Noise Speaker so that its sound would be directed across the center path of the DUT.
- Set the center of the Noise Speaker cone to an elevation of 1 m.
Connect and testing laptops and speakers
- Ensure that the Noise Laptop has the "FAR Test" folder, the (stationary) noise sound, and the music playlist specified in Audio source files.
- Connect the Noise Laptop and the Noise Speaker with an audio cable.
- Ensure you can play any of the audio files from the Noise Laptop, including the "Happy" song described in Music (audio) account setup.
- Ensure the Speech Laptop has the "FRR_RAR_utterances" and "WWDD_utterances" folders.
- Connect the Speech Laptop and the Noise Speaker with an audio cable.
- Ensure you can play any of the audio files from the Speech Laptop.
Position the Echo Dot
When testing the Echo Dot, position it in the same location where the DUT was located for its tests. If any special mounting or stand is needed for the Echo Dot, now is the time to determine what is needed for you to be able to swap the DUT and Echo Dot between tests.
When you're finished positioning the Echo Dot, position the DUT back in its original location before further configuration or tests. (Exception: for the FAR test, both the DUT and Echo Dot are tested simultaneously, and the devices need to be next to each other during the test.)
Now that your test room is configured, learn to Calibrate your Setup so that your device can yield test results similar to that of Amazon's acoustic test environment.