Add SOUND and SSP-SIR algorithms #32

[ISSUE TRANSFERRED FROM MNE-PYTHON REPO by drammock on 2026-04-20]

Dear MNE-Python developers,

I am Matteo De Matola, doctoral student at the University of Trento (Italy).

I have noticed that MNE-Python does not include an implementation of the SOUND (Mutanen et al., 2018) and SSP-SIR (Mutanen et al., 2016) algorithms. These algorithms are widely used in TMS-EEG preprocessing, but to the best of my knowledge, they are currently implemented in MATLAB only.

The absence of a reliable Python implementation for SOUND and SSP-SIR does not facilitate the adoption of MNE-Python in the TMS-EEG community. In agreement with Tuomas Mutanen, the inventor of the two algorithms, I volunteer to translate them from MATLAB to Python and integrate them into MNE.

I did not open an ENH-type issue because:

1. I do not have a proposed implementation yet
2. I want to add the feature, rather than request it

If you confirm that the two algorithms are not included in MNE-Python and agree to their inclusion, I will follow up with a proposed implementation ASAP.

Thanks,
Matteo