If it doesn't, does it hinder giving the spirits you conjure directions?

If it does, does it hinder you from calling on spirits you have already conjured & bound?

Good questions, I'd say it prevents conjuring because it doesn't allow the mage to speak. Calling I'd say you can do it but you'd have to beat the composure test. However you still can't speak.

because it doesn't allow the mage to speak.
The Mage doesn't need to Speak to Summon or Bind a Spirit nor for casting Spells.
Only concentration.
And a Magemask prevents Concentration

with a concentrated Dance
Medicineman

/clap
I admit it I lol'ed.

Mage masks would be pretty worthless if any mage could just summon a spirit to take off the mask. Thats why I love Mage Cuffs. Trying to cast a spell Zzzzzzaaaaaaap!

Right, but there's lots of worthless things in the game. Adrenal pump, most of the firearms(yes there's 1 or 2 in each class that are better than the rest in some way.), supposedly recreational drugs which are better used as weapons.

Which brings me to my next point. Don't mage-mask the mage. Drug him.

I prefer to just shoot the Mage until they get sleepy.

Would use of a Centering technique help offset the distractions going? As I recall the hoods come with white noise generators and crap like that. Centering is all abotu focusing though. Hmm...

This is a good question. The whole SR-system has not one single item that simply DOES something and you can´t do anything against it (immortal elves don´t count). If you see it this way, the magemask is terribly broken. If it would be "subtracts [rating] dices from your spellcasting-test" or if it would work like the magecuffs i wouldn´t have a problem with it. So if you are trained enough (and nobody is more trained in concentrating than a mage) it shouldn´t be impossible to cast or summon while wearing the mask. (Caution: houseruling)

Quick thought- If you are in a Mage Mask you are most likely be held somewhere. Maybe shell out the nuyen and make that room warded, so even if you manage to summon a spirit, it's not going to get far. Or at least it's going to have a small hurdle before doing whatever.

Hmm, might need to work up something like this to happen to my group, cue evil GM chuckle.