Headphone break in?

Do people break in headphones? My step son just got Seinhausser HD-595's. He asked me and I don't remember ever breaking in any of my headphones.
You could let them break in while listening.They do need to loosen up like new speakers do.♫
Thanks Hifitime. I read some ineresting info on head-fi that indicated it was recently proven that speakers do break in. I'm with you that you might as well be listening while you're doing it.
Quoting from myself in this current thread:
I have an older pair of Stax Lambda Pro's (non-Signature) with an SRM1-MkII solid state amplifier. I've found that ever since they were new, 20+ years ago, they have needed to periodically (perhaps once a month) have a severe "workout," playing at least a full album at volume levels that are higher than I would want to have reproduced next to my ears. Otherwise they sound very thin. I presume that the diaphragm needs that periodic workout to maintain the flexibility it is supposed to have.
This effect is NOT subtle. I have no feel for the extent to which it may apply to other headphones. Note that the STAX's are electrostatic, while your Sennheiser's are more conventional dynamic headphones.

-- Al