OSHA's Permissible Exposure Limit (PEL) for noise is 90 dBA for an 8-hour workday.

Tinnitus, hyperacusis, and dizziness are all common symptoms of noise-induced hearing loss.

Temporary Threshold Shift (TTS) is the temporary loss of hearing that can occur after exposure to loud noise.

Earmuffs, earplugs, and active noise-canceling headphones are all common types of hearing protection devices.

The recommended noise level for a classroom is 30-35 dBA.

Traffic, construction, and airplanes are all common sources of noise pollution in urban areas.

Noise is the unwanted sound that is generated by a machine or other device.

Decibels (dB) are a common unit of measurement for noise level.

Propagation time is the time it takes for a sound to travel from one point to another.

Fiberglass, mineral wool, and acoustic foam are all common types of soundproofing materials.

Reverberation is the phenomenon where sound waves bounce off of surfaces and create echoes.

Adding sound-absorbing materials, installing soundproofing panels, and using a sound masking system are all common methods for reducing reverberation in a room.

Sound absorption coefficient is the ability of a material to absorb sound waves.

Double-glazed windows are a common type of soundproofing window.

Sound transmission loss is the ability of a material to block sound waves.