Simulating a room with no echo

[drydenwiebe]

Hello!

I have a question about simulating audio with a very simple source/mic setup.

I know that what I am trying to do is not quite the intention of this library, but I want to prototype an algorithm on the simplest indoor acoustics setup before trying it on more complicated setups (with more complicated room geometry, echoes etc...).

I am trying to model a simple scenario where the sound is not bouncing off walls, but rather just returning the sound as it hits the mics directly for each mic without any indirect sound source. I would guess that the way to do this would be by setting ``max_order=0``` but this does not seem to work as there is echoes still.

Setting the wall material for a simple square room to be (1.0, 1.0) which corresponds to full absorption seems to give me the desired results but I think there must be a better way to do this.

Here is a notebook that is based off of the example room notebook that illustrates my issue. It is also attached as a zip file to this issue, github does not allow ipynb as attachments. no_echo_demo.zip

Thank you so much for your time!

[fakufaku]

Hi @drydenwiebe , this is actually a fairly natural thing to try! Try without echoes first, then move on to the harder case 😄 We are actually working on adding a new object class just for that (see PR #224 ). I think it should get merged pretty soon.
Nevertheless, it should work also by setting max_order=0.

I have checked your script and you are calling

room.set_ray_tracing(receiver_radius=0.5, n_rays=10000, energy_thres=1e-5)

which will simulate reverberation (echoes!) using the ray tracing method.
If you remove this line, it should work as expected.
You are setting ray_tracing=False in the constructor, but calling set_ray_tracing will turn it back on.

[drydenwiebe]

Hi @fakufaku, thank you so much for the response!

I see what the issue was, makes sense. Out of curiosity when I called set_ray_tracing the simulator is then set to use the hybrid ray tracing/image method, or just ray tracing. If so is there a way to only use ray tracing?

Thank you!

[fakufaku]

You can disable the image method by setting max_order=-1. This will even ignore the direct sound. If you want to keep the direct sound, you can set max_order=0.

You can also enable ray tracing in the room constructor directly.

[drydenwiebe]

Ah I see, makes sense. Thank you!