The miniDSP UMA-8 microphone array, with onboard direction detection, echo cancellation, and noise reduction, has a wide variety of applications. In this app note we'll run through its use with Siri, the "intelligent virtual assistant" from Apple loaded on OSx.

Note: this app note applies only to desktops and laptops running MacOS. The UMA-8 typically requires more power than can be supplied by phones and tablets.

Why use the UMA-8?[Top]

By default, Siri would use the inbuilt microphone in your computer. This is fine if you are sitting at the computer, but for use of these programs as a "far field" hands-free assistant a more sophisticated microphone is needed. The UMA-8 has:

  • Beam-forming running across an array of 7 microphones to improve voice detection and eliminate extraneous noises.

  • Echo cancellation and noise reduction to reduce the effects of non-voice sounds (like music playing) and noise (traffic, kitchen noises etc).

The UMA-8 is "plug and play" – you do not have to configure anything to make it work with Siri. If you wish, however, you can use the miniDSP plugin to tweak the processing parameters of the microphone array (recommended for advanced users only!)

Using the UMA-8 with Siri[Top]

Plug the supplied USB cable into the micro-USB port on the UMA-8, and plug the other end into a spare USB port on your Mac. Open System Preferences and then Sound, and select the miniDSP micArray as the input source:

Selecting the UMA-8 microphone array for Siri

To enable Siri to respond to hands-free voice commands ("Hey Siri") on the Mac, you will need to a. set up a keyboard shortcut and b. map the keyboard shortcut to a voice command. This is described in this article on MacWorld:

And that's it! You should now be able to say "Hey Siri" from anywhere in the room to activate it. Check out the section Apple's help page for more details on Siri.

macos sierra siri waveform

Further experimentation[Top]

By default, the UMA-8 is configured for automatic direction detection. You can alter the behavior with the switches on the board as follows:

  • SW1: enable and disable microphone beam-forming.
  • SW3: manually select direction of beam-forming.
  • SW4: enable and disable automatic direction detection.

Note that the LEDs around the edge of the board (on the underside, if the switches are on the top) will indicate the direction of beam-forming.

After some experience with the setup, you may wish to tweak the audio processing parameters of the UMA-8. Start the miniDSP micArray configuration program and click the Connect button to change parameters. For example, to turn on the automatic gain control and increase mic signal levels, try settings like this:

miniDSP UMA-8 microphone array AGC settings

Wrapping up[Top]

That's it for this app note! Have fun, and please let us know about your UMA-8 and Siri experience in our forum.


Related Products - USB Microphone Arrays