DXOMARK’s Audio Lab is a solution designed to let you perform the same kinds of perceptual evaluations that are part of DXOMARK’s smartphone audio testing protocol. This solution was specifically built to reproduce realistic use cases that smartphone consumers encounter daily, giving you the opportunity to assess the quality of both speakers and microphones under real-life conditions.
The Certified Audio Lab comes with multiple tools that allow you to perform the same tests that DXOMARK runs. Indeed, the Certified Audio Lab gives you access to a full kit for performing recording perceptual testing, as well as another kit for performing playback perceptual testing. The optional DXOMARK Listening Room ensures that all indoor tests are performed in a uniform environment under the same audio conditions.
Recording Kit
Coming with a set of 16 speakers (8 for ambient sound, 8 for voices), their dedicated holders, as well as a holder for an outdoor setup, the Recording kit allows you to put a device through all the different use cases designed for this part of the testing, which uses 3Pass Lab software (not included in the Audio Lab package).
Listening Room
A 2.5×2.5×2.2m box tailored to host the Playback and Recording kits and to perform tests under controlled conditions. Easy to mount and unmount, it has been designed for both optimal performance and convenience.
Playback Kit
Designed to evaluate smartphone speaker attributes in a comparison against other devices through various use cases such as gaming, watching videos, and listening to music (thanks to a unique, homemade playlist created specifically for testing). The kit includes a set of holders for testing up to four smartphones in the listening room when performing all the playback evaluations, along with four reflectors that are used specifically for the spatial evaluation.
Wind noise attenuation
DXOMARK’s Wind Noise Lab is a hardware and software solution that employs a documented and rigorous methodology for evaluating the impact of wind on audio quality and for assessing the effectiveness of wind noise processing during audio recordings. In addition to the hardware setup and controlling software, DXOMARK provides documentation and training on how to judge the quality of a device’s wind noise mitigation.
The hardware test kit includes:
● Four monitoring speakers for playing all kinds of audio content from different source positions;
● A wind generator that can be set to a wide range of wind speeds, from light breeze to gale (1.5 m/s to >16 m/s) at test position;
● A 360° rotating smartphone holder to allow testing at any angle of wind incidence.
The controlling software allows you to manipulate each part of the setup independently, as well to automatize recording sequences with custom audio content, wind speeds, and smartphone angles. DXOMARK wind noise test tracks are part of the package, these include voice male and female voice content, urban background and correlated pink noise.
To perceptually assess the effectiveness of wind noise processing, the device under test records voice content under conditions of no wind, light wind, moderate wind, and strong wind at both 0° and 90° angles. Our engineers apply a grade from 0 to 5 to each recording, based on speech intelligibility when compared to the reference (no wind) recording.
In addition to perceptual evaluation, you can perform objective tests using equipment and protocols that are common in the audio industry to further characterize wind noise reduction performance based on such metrics as wind reduction ratio, wind spectral energy, and signal average correlation vs reference signal. DXOMARK will provide you with all the information you need to perform these tests according to our protocol.
Audio zoom (microphone directivity)
When taking a video of a person speaking, you have the option of using the camera to zoom in on the speaker’s face. But is your phone’s microphone capable of zooming in on the speaker’s voice so that it stands out above the background and competing noises? The popularity of smartphone videography is making consumers more aware of audio quality and raising their expectations for features such as audio zoom and microphone directivity.
Audio Zoom Lab is a new testing protocol designed to evaluate the audio zoom performance of smartphones in a semi-anechoic chamber. In addition to providing testing and benchmarking services, we also provide the lab equipment to perform the evaluation as we perform it in our facility. Our Audio Zoom Lab system consists of two parts: the hardware setup and a controlling system for automated and remote recording. The product comes with a comprehensive documentation and training package that covers the installation, operation, and perceptual assessment of the audio zoom performance.
Our Audio Zoom Lab setup includes three monitoring speakers to play different sound contents for the corresponding use cases. A 360° rotating smartphone holder allows testing for smartphone directivity, and the dedicated controlling software system enables the manipulation of speakers and the rotating smartphone holder, as well as the automation of the recording sequences. Additionally, we provide our audio zoom test tracks, which include voice and musical content for perceptual evaluation, as well as a log sweep for objective directivity recording.
The objective test records a 5-second logarithmic swept-sine after every 10° rotation to measure the smartphone’s directivity. With the recordings, our software provides each device with its directivity graphs in different zoom ranges and frequencies bandwidths. This gives a first analysis of the audio zoom functionality. The perceptual evaluation contains two different use cases: speech and music. The device records speech and music content in front of the smartphone at different zoom ranges, with two speakers behind the device playing the background noise. Our sound engineers then evaluate the recordings based on several attributes, including timbre, spatial, volume, artifacts, and background. We provide all the necessary testing standards and tips in our training package.
With our Audio Zoom Lab solution, we are committed to providing a professional and reliable audio zoom testing solution that meets the rigorous standards of the smartphone industry. Contact us to learn more about our solutions and services and how we can help you evaluate the audio zoom performance of your smartphone products.
Playback Measurements
Using updated Audio testing tracks that include white noise, pink noise, logarithmic swept sine (also known as a chirp), along with classical, electronic, hip hop, and other various music signals, DXOMARK Audio engineers have frequency response measurements and total harmonic distortion with noise (THD+N).
Test results show the ratio of the root mean square (RMS) values for distortion and noise signal, as well as the RMS values for the entire signal. The smaller the harmonic distortion and the less noise a device’s speaker produces, the better. While a topic for discussion in the high-end and audiophile space, a distortion below 2 to 3% is generally perceived as not affecting the audio rendition.
