Sound direction

This is where you talk about the NXJ hardware related topics such as the brick, sensors, LEGO pieces, etc.

Moderators: imaqine, 99jonathan, roger

Advanced Member
Posts: 181
Joined: Sun Oct 14, 2007 11:21 am

Sound direction

Postby ruperty » Tue Feb 04, 2014 4:27 pm


I am trying to get the NXT to turn and fixate on to a sound-emitting target.

I had expected that the sound sensor would have the greatest reading pointing towards the sound, but it doesn't seem to be so simple. I seem to get larger readings when the sensor is side-on.

Is there a way to make the sound sensor directional?

leJOS Team Member
Posts: 312
Joined: Tue Apr 26, 2011 9:18 pm
Location: Netherlands

Re: Sound direction

Postby Aswin » Tue Feb 04, 2014 6:28 pm


Interesting problem. I cannot recall other likewise experiments with the NXT or EV3.
You could think about the following.
- make an accoustic lens to make the sensor more directional. You'll need some kind of parabolic surface that reflect sounds for this.
- use two sensors and measure time difference between the two. Given the low sample rate of the brick you'll need to place both sensors far apart for this to work. I doubt this will work.
- create two sound channels to the sensor and utilize the effects of phase differences to locate the source.

But I would start with trying to understand what exactly is happening. A plot of sound level against angle would make a nice start.

My NXT blog:

Return to “NXJ Hardware”

Who is online

Users browsing this forum: No registered users and 1 guest