Noise

Noise is often defined as "unwanted" sound. In the workplace, noise can have varying effects based on the sound level, frequency, and amplitude, and the task being performed. In general, noise acts as a stressor in the work environment. Noise effects fall into several categories:

• Annoyance - Annoyance noise has minor effects on performance, but can lead to psychological effects such as irritability, frustration, and anger.
• Task Interference - Noise interference can adversely effect tasks requiring vigilance, steady posture, uninterrupted vision, information comprehension, response flexibility, serial responding, or short-term memory (STM). STM has limited capacity and duration. Noise distraction before or during STM rehearsal to encode information can cause the information to be wiped out and lost.
• Exacerbation of Fatigue - Sustained high noise levels can contribute to overall fatigue with attendant higher error and accident rates.
• Hearing Loss - Noise is the primary cause of hearing loss. Most hearing loss occurs in the higher frequencies at about 3,000-6,000 Hz. This creates difficulty in understanding speech, particularly consonant sounds. Also, hearing loss does not just bring "silence." Often it is accompanied by a constant ringing in the ears (tinnitus).

Sound Frequencies Affected By Hearing Loss

Graphic from the House Ear Institute, Los Angeles CA