How to get **Voice** attributes via script?

I’d like to modify the global Voice attributes, such as Pitch Shift and Tension via scripting.

Specifically, I’ve got a script that will duplicate an existing track for the purpose of doubling the vocal. I can modify the attributes of the Note. I can also access the Automation values.

However, I just want to change the default values found in the Voice panel, not insert automation values on the timeline.

How can this be done via scripting?