Measurement of Noise:
– Sound is measured based on amplitude and frequency of a sound wave.
– Amplitude measures the forcefulness of the wave.
– Energy in a sound wave is measured in decibels (dB).
– Pitch describes the frequency of a sound and is measured in hertz (Hz).
– Instruments like Sound Level Meters and Noise Dosimeters are used for measurement.
– A-weighting or ITU-R 468 weighting is used to measure signal noise.
Sources and Effects of Noise:
– Audio noise in recording systems refers to residual low-level sounds like hiss, rumble, crackle, and hum.
– Noise can be caused by equipment, instruments, or ambient noise.
– Environmental noise includes noise from vehicles, aircraft, trains, and industrial sources.
– Exposure to noise can lead to health issues like hearing loss, high blood pressure, and sleep disturbances.
– Prolonged noise exposure can trigger stress responses in the body.
Regulation and Policies:
– Noise regulation includes statutes and guidelines set by governments.
– Laws and standards govern environmental noise levels for specific land uses.
– The Noise Control Act of 1972 aimed to promote a healthy living environment.
– The Quiet Communities Act of 1978 focused on noise control programs at state and local levels.
– Noise ordinances in U.S. cities regulate noise levels.
Prevention and Protection Measures:
– Noise-induced hearing loss is permanent but preventable.
– Workplace regulations may limit noise exposure.
– OSHA requires hearing protection, but improper use may not reduce risk.
– Measures like engineering noise control and Safe-In-Sound award help prevent hearing loss.
– Employers should provide hearing protection devices to workers.
Technological Advancements and Research:
– Smartphone apps can measure sound levels accurately.
– Studies analyze the non-auditory effects of noise pollution on health.
– Organizations like CDC focus on noise and hearing loss prevention in the workplace.
– Research examines the relationship between noise exposure and public health.
– Various publications offer insights into the impact of noise on stress, health, and quality of life.
Noise is unwanted or harmful sound considered unpleasant, loud, or disruptive to hearing. From a physics standpoint, there is no distinction between noise and desired sound, as both are vibrations through a medium, such as air or water. The difference arises when the brain receives and perceives a sound.
Acoustic noise is any sound in the acoustic domain, either deliberate (e.g., music or speech) or unintended. In contrast, noise in electronics may not be audible to the human ear and may require instruments for detection.
In audio engineering, noise can refer to the unwanted residual electronic noise signal that gives rise to acoustic noise heard as a hiss. This signal noise is commonly measured using A-weighting or ITU-R 468 weighting.
In experimental sciences, noise can refer to any random fluctuations of data that hinders perception of a signal.
English
Etymology
From Middle English noyse, noise, from Old French noise (“a dispute, wrangle, strife, noise”), of uncertain origin.
