The Musical Articulation Test Tones (MATT) is a modulated sweep signal developed by Art Noxon at Acoustic Sciences Corporation to test room acoustic performance.

About MATT test

More about MATT test

The signal can be played through a high fidelity sound system to reveal issues with a room's acoustics. This signal can be listened to from the listening position to reveal audible issues, and it can also be recorded and then analyzed with special software to find out what frequency zones are most problematic and get an overall assessment of a room's acoustical performance in the bass and lower midrange frequencies. To get an analysis has so far required the user to send a recording of the MATT playing in their room back to Acoustic Sciences Corporation, where a specialized script is then run to analyze the signal and generate a report.

A long term goal has been to make this test easier for end users to execute and analyze. One difficulty has been making it easy to know what frequency a listener is hearing when they hear problems. Another has been to allow an end user to get an automated computer analysis of the results that is graphically explicit and clear, and allows them to get more insight into what the results mean. Ideally an end user could look at a graph of the results that shows score and graphed response at various frequencies, and then allow them to play it back again in its entirety, or select problematic areas and play just those, and allow a quick comparison of what the problem area sounds like compared to the reference signal. This listening would be done using headphones because they don't suffer from room acoustic issues, so the differences can be clearly heard.

I've been working on a project to develop a web browser based MATT analyzer tool that will allow end users to load a recording they've made and have it automatically graphed and evaluated. The initial learning curve has been around getting access to the data stream using web audio APIs available in Javascript. One issue was getting RMS averaging levels that were over short enough duration to show the detail that the MATT analysis requires. This has been solved adequately now. To make this analyzer more useful will require user interface improvements for playback, along with options to record directly from a device such as a phone or tablet, or PC with a microphone attached. This will allow an end user to use their phone, tablet, or PC to send the test signal to their audio system and then record the results and get the analysis all in one step from a single device.

To do list:

• Allow recording the MATT directly from a phone or other web device.
• Enable touch screen support and auto detect various devices screen size and orientation to automatically optimize layout appropriately.
• Allow saving recordings as web browser cookies
• Allow deleting recordings
• Allow re-naming recordings and adding notes
• Improve playback and selection controls
• Change layout so that there's only one graph showing at a time, with an option to show overlays of multiple measurements on the same graph
• create an auto loop playback function that will play a short selection repeatedly, alternating between the recorded result and the MATT reference file itself