Pandemonium

From Manual of the Planes (3e):

It is a place of howling, screaming winds.

It is an underground realm of stygian darkness.

It is where sanity is besieged by unending madness.

Pandemonium is a great mass of matter pierced by innumerable tunnels carved by the howling winds of the plane. It is windy, noisy, and dark, having no natural source of light. The wind quickly extinguishes normal fires, and lights that last longer draw attention of wights driven insane by the constant howling wind.

Every word, scream, or shout is caught by the wind and flung through all the layers of the plane. Conversation is accomplished by shouting, and even then words are spirited away by the wind beyond 10 feet.

The stale wind of Pandemonium is cold, and it steals the heat from travelers unprotected from its endless gale that buffets each inhabitant, blowing sand and dirt into eyes, snuffing torches, and carrying away loose items. In some places, the wind can howl so fiercely that it lifts creatures off their feet and carries them for miles before dashing their forms to lifeless pulp against some dark, unseen cliff face.

In a few relatively sheltered places, the wind dies down to just a breeze carrying haunting echoes from distant parts of the plane, though they are so distorted that they sound like cries of torment.

Erythnul, the Lord of Slaughter, makes his terrible domain on Pandemonium.

Pandemonium has four layers: Pandesmos, Cocytus, Phlegethon, and Agathion.

The name Pandemonium means "uproar and commotion." As its definition implies, the features of Pandemonium are numerous and tumultuous.

There are four layers on Pandemonium, and the terrible windstorms can blow through any one of them. Vision on Pandemonium is much like any deep underground locations on the Material Plane where there is no natural light.

The constant screams of the wind make it impossible to hear anything beyond 10 feet. Likewise, spells and effects that rely on sonic energy have their range limited to 10 feet. Travelers are temporarily deafened after 1d10 rounds of exposure to the winds, and permanently deafened after 24 hours of exposure. Temporarily deafened characters regain their hearing after 1 hour spent out of the wind.

Ear plugs or similar devices negate the deafening effect. Of course, wearing ear-plugs effectively mimics the normal effects of being deafened.