Every single telepath has had problems with probing Sabetooth for information. And after he got that claw stuck through his head it made things even harder. That's how Psylocke got gutted. Heck even before the claw in the head Psylocke had problems. This applies to Xavier and Jean as well. And the latest being Mindee.
However Emmas still able to get bits and pieces of information from her probes.
Probing is different from other forms of telepathy
Just a side note:
Here's Emma after getting speedblitzed by Aurora and Northstar. And here her and Cable talk about Sabertooth. Their conversation shows that probing is different from other forms of telepathy. More examples are at the back of the thread where Emma uses unorthodox methods of telepathy to take out Wolverine who has similar psi-defences to Sabertooth.
Here's the entire ordeal. Emma tries to discover the problem behind Roberts mental breakdown. While searching she eventually discovers that an old associate of hers Jason Wyngarde was the culprit behind it all. Wyngardes powers work easier on more powerful minds. For example when he drove the Phoenix Force replica of Jean Grey insane and when he placed Emma Frost in a psychic coma which she eventually escaped from.
Robert himself is an individual with immense psionic power. Masterminds psychic virus coaxed him into erasing his existence from every individuals minds on the planet. Upon this relevation Robert tries his hardest to resist Emma's help, however Emma manages to continue to plow through his mind, she locates his wife whose all the way in a S.H.I.E.L.D hellicarrier and pulls her subconscious into Roberts mind. Emma eventually calms Robert down and then reverses the damage Wyngarde caused.(She knows how Wyngardes powers work better then he does. That's probably how she escaped the coma he placed her in.)
On a side note. Emma mentions that Reed is the only one who knows about all of Roberts secrets. However she just had a rumage through both Reeds and Roberts thoughts so surely now she also knows all about the Sentry, his past and secrets etc?
Jason Wyngardes abilities work easier on powerful minds as stated in the scan above. That's how he was able to drive the PF insane and mind f*ck the Sentry.
Here he places Emma in a coma, which Emma manages to fight her way out of. As shown in the above scans, Emma knows how Wyngardes powers work better then he does.
Here's the insane Phoenix Force duplicate of Jean Grey. Emma built that mind trap device.
The Kingmaker is a mutant who has the ability to grant one wish for an individual, but that person will have to do something in return to make it last. Emma once kicked him out of the Hellfire Club when she was White Queen. Here she uses her influence to save him from going to prison in return he leaves her Hellions alone.
Emma's abilities are inhibited by Leech, so to break free she has to kick poor kid, knocking him out. Though she regrets about that action, that was the only way for her to escape.
The following incident with "surprise" from Dark Beast- an explosion- shows how much PIS was that "brick incident" from New X-Men. She senses the explosion psionically- barely in time to warn her students.
We get to see a bit of Emmas past here. The Phoenix no doubt overpowers Emma here. But seeing how the Phoenix is a cosmic being I think this is still a good feat. Even though Emma gets utterly destroyed she still puts up some resistance and manages to hold out on that memory Jean wants to know so badly about. Granted a few more rounds with the Phoenix and she would have been a vegetable. It should be noted that Jean/Phoenix never picked up on the Cassandra Nova/Hellfire Club/Team wrecking Survivors guilt thing.(Emma trapped Nova in stuffs body before this event).
In her training session with Astrid Bloom Emma learns how to affect animal's minds, changing their behavior. That's the skill Emma learned along with any other Astrid's skills
Emma & Banshee in the flight
Emma psionically navigates Banshee at St Louis despite distractive effects of his scream...but finally shuts him down when she decides that her ears got enough of it.
So, intense sound isn't a major distraction to her.