Audio lab

AN END USER-CENTRIC audio testing solution

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.

Measure sound the way people experience it

Perform the same perceptual analyses as DXOMARK…

…with the tools included in the Audio Lab

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.

Introducing DXOMARK’s playlist

As part of the Audio Testing Tracks, which also include specifications for movie trailers and audio game sequences as well as for voices and ambient background mixes for recording tests, DXOMARK commissioned artists to produce pieces of music that would truly highlight every tested attribute (timbre, spatial, dynamics, volume, artifacts, background). What makes this playlist truly unique is that it has been designed to respond to each and every requirement of the playback protocol. The playlist features 10 tracks composed by four musicians who were handpicked for this exact purpose, and it covers a wide variety of genres:

  • The TR 909 snare drum in The Forest is very useful for evaluating wideness and bass precision.
  • No One Outside‘s kick and bass are particularly appropriate for highlighting distortion.
  • In Push the Limit, the snare hits, predominant vocals, and synthesizer allow for precisely evaluating midrange frequencies, distance, attack, and global tonal balance.
  • The strong snare drum and crisp hi-hat cymbal found in Switch Town offer a perfect setting to listen for attack and punch.
  • AlexEno features a sharp piano rendering to evaluate attack.
  • Sin Volver‘s guitar, piano, and hook are the perfect tools for evaluating treble and tonal balance.
  • The EDM track Be Alone, featuring strong bass and compression, allows for accurate pinpointing of temporal and spatial artifacts.
  • Built around tambourines, piano, and strings, Petit Jean‘s orchestral arrangement helps evaluate treble and tonal balance.
  • The Jazz Improvisation features a variety of instruments that allow for a complete evaluation of the spectrum, with soft bass for the lower frequencies, saxophone and piano for the midrange frequencies, and cymbals for attack.

You can find more about how DXOMARK’s playlist was built here: Introducing DXOMARK’s new testing playlist, and the music(ians) behind it

Extract of Romain Seo’s No One Outside, The Forest, Push the Limit and Switch Town

Extract of Raphaël d’Amours’ Cold Nights and AlexEno

Extract of David Starck’s Sin Volver, Be Alone and Petit Jean

Extract of Happy Hours’ Jazz Improvisation

Wind noise attenuation

Use a setup that includes a wind generator, speakers, software, and precisely characterized recordings to measure how well a smartphone attenuates wind noise.

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Audio zoom
(microphone directivity)

Objective and perceptual sound tracks, and a rotating holder to measure a device’s audio directivity when using telephoto and super-telephoto zooms.

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Playback Measurements

Measure the sound output’s total harmonic distortion and noise (THD) using music and white noise, pink noise, and other specially designed sound tracks.

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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.