Does Dark Whispers affect the user?

[ATHATH]

An excerpt from the Dark Whispers feat, from the Elder Evils sourcebook:

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In addition to the basic uses of the Dark Speech, you can whisper words of incredible wickedness to form grotesque visions in the minds of those who hear you. All living creatures within a 30-foot radius that can hear your words must make Will saves (DC 10 + 1/2 your character level + your Cha modifi er). On a failure, creatures with fewer Hit Dice than you are staggered for 1d10 rounds; those with as many or more Hit Dice are confused for 1 round. This is a mind-affecting, supernatural effect.

Whenever you use Dark Speech in this manner, you take 1 point of Charisma damage.
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Compare this to something like the Dread function of the Dark Speech feat, which was reprinted in Elder Evils and is a prerequisite of Dark Whispers:

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Dread: Whenever you use Dark Speech in this manner, you take 1d4 points of Charisma damage, and every other creature in a 30-foot radius must attempt a Will save (DC 10 + 1/2 your character level + your Cha modifier). The result of a failed save by a listener depends on the listener's character level and alignment, as detailed in the table below.
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Does Dark Whispers affect the user if they can hear themselves? If so, are you able to, like, plug your own ears with your fingers to avoid that as a free action or something?

Bonus question: Does the Dread function of Dark Speech affect even deaf creatures, since it doesn't specify that they have to be able to hear you? Can it affect non-living creatures (and creatures that are immune to mind-affecting effects), since it doesn't have those same clauses that Dark Whispers has?