Add a notebook that shows a basic binaural synthesis

[pingelit]

Open questions:

• the interactive part seems to break the build process. Am I doing something wrong? @mberz ?

[mberz]

Please refer to nbsphinx's docs section on how to use interactive widgets in nbsphinx.
https://nbsphinx.readthedocs.io/en/0.9.3/code-cells.html#Interactive-Widgets-(HTML-only)

[mberz]

On the issue, that the tests are failing on CircleCI:
Please run

pytest --nbmake docs/gallery/interactive/*.ipynb

locally and check what is causing the issue. On my machine it seems that the interpreter is "stuck" somewhere and does not continue, maybe pausing and waiting for user interaction or similar.

[mberz]

The nbmake issue seems to be unrelated to, but caused by something else...

[mberz]

Please merge the most recent state of the main branch for a workaround to the issue.

[pingelit]

Please refer to nbsphinx's docs section on how to use interactive widgets in nbsphinx. https://nbsphinx.readthedocs.io/en/0.9.3/code-cells.html#Interactive-Widgets-(HTML-only)

The problem is the interactive_output. I guess this is too complicated for a pre-rendered html document. I will keep the example commented out. We could add a comment saying that this would have to be run in binder?

[sikersten]

Thanks for the effort! Great example!

[pingelit]

Thanks for the review!

[mberz]

I have a couple minor comments (haven't really focussed on the text)

I'd very much suggest making this notebook statically rendered to circumvent having commented out code in the example gallery. This feels rather unfinished and counterintuitive for people who are novice with pyfar or python in general.

[mberz]

Suggested change

	"`pyfar` includes a [method to load specific HRIRs from the dataset](https://pyfar.readthedocs.io/en/stable/modules/pyfar.signals.files.html#pyfar.signals.files.head_related_impulse_responses) but the example shown here is the general approach for loading a SOFA file.\n",
	"pyfar includes a [method to load specific HRIRs from the dataset](https://pyfar.readthedocs.io/en/stable/modules/pyfar.signals.files.html#pyfar.signals.files.head_related_impulse_responses).\n",

[pingelit]

I think the sentence does not make sense without this. Or should we then add the suggestion by sikersten?

[mberz]

Yes, see my comment on Simons review comment ;)

[pingelit]

I think I shouldn't work after hours 😅🤦

[mberz]

The output of this is heavily distorted. I can with no good conscience agree that one can well make out that it is the horizontal and vertical planes. It does look like they are not orthogonal, but rotated.
Please add

Suggested change

	"sources.show()"
	"ax = sources.show()",
	"ax.set_box_aspect([",
	"np.ptp(coordinates.x),",
	"np.ptp(coordinates.y),",
	"np.ptp(coordinates.z)])"

or use the scatter plot implemented in spharpy

[pingelit]

Thanks for pointing this out .. due to pyfar/pyfar#555 this does not work yet.

[pingelit]

Nevermind.

[mberz]

You can also use

import matplotlib.pyplot as plt
ax = plt.gca()

as workaround

[mberz]

same comment as above

Suggested change

	"sources.show(index)"
	"ax = sources.show(index)",
	"ax.set_box_aspect([",
	"np.ptp(coordinates.x),",
	"np.ptp(coordinates.y),",
	"np.ptp(coordinates.z)])"

[mberz]

Is there something missing here? Looks like a falsely managed merge conflict?

[pingelit]

Yep

[mberz]

Is it just me, or are these not 100% anechoic? I feel like there's a reflection in there.

[mberz]

I've implemented a hot fix for the scaling of the scatter plot within pyfar, so we can get rid of the manual axis scaling in the future.

pyfar/pyfar#554

[pingelit]

Thanks for the reviews. I think I got most things now.

[hoyer-a]

Thanks, the interactive example is great!
Just some minor propositions and typos.

[hoyer-a]

If binaural signals perfectly reproduced at the ears of a listener, for example via headphone playback, this will evoke an auditory illusion of a virtual sound source that can be placed at an arbitrary position in space.

Something went wrong with this sentence

[pingelit]

I think it's okay. What would be your suggested change?

[hoyer-a]

"If binaural signals are perfectly reproduced"

[pingelit]

Ah yes, fixed this in my latest commit. Thank you for the clarification.

[hoyer-a]

Suggested change

	"Such a reproduction of binaural signals is termed _binaural synthesis_, and the examples below show how this can be realized with a special filters and anechoic audio content.\n",
	"Such a reproduction of binaural signals is termed _binaural synthesis_, and the examples below show how this can be realized with special filters and anechoic audio content.\n",

[hoyer-a]

Maybe add an indication for 0° azimuth in the plots for orientation.

[pingelit]

sikersten and I came to the conclusion that we want the code to be as simple as possible. I feel like adding an indication for that would go against this. But it might also help with the context.

[hoyer-a]

Suggested change

	"With an HRIR selected, we can plot it in the time and frequency domain."
	"With an HRIR selected, we can plot it in the time and frequency domain. As expected, time differences and frequency dependent level differences can be seen in the plots"

[hoyer-a]

Suggested change

	"First,the audio signal is loaded and plotted in the time domain.\n",
	"First, the audio signal is loaded and plotted in the time domain.\n",

[sikersten]

I would have a few suggestions to slightly shorten the code. Otherwise approved :)

[pingelit]

Regarding the plots with the source positions, sikersten and I decided to remove the styling and rather wait for the fix in pyfar.

[sikersten]

Thanks! Minor comments left:

• pyplot and sofar imports are obsolete
• Formulation "level diffrences can be seen in the the plots." could be shortened to "are visible."
• binaural_audio = pf.dsp.normalize(binaural_audio) is obsolete