Noise

Noise refers to unwanted sound,Britannica, “Noise,” Britannica.com, https://www.britannica.com/science/noise-acoustics, accessed May 2025. typically perceived by the ears. It can cause damage to hearing.WHO, “Deafness and hearing loss: Safe listening,” Questions & Answers, https://www.who.int/news-room/questions-and-answers/item/deafness-and-hearing-loss-safe-listening, accessed May 2025. In physical acoustics, noise often results from irregular or unwanted vibrations transmitted through a medium.Britannica, “Sound,” Britannica.com, https://www.britannica.com/science/sound-physics, accessed May 2025. Prolonged exposure to loud noise can lead to hearing loss, a condition called deafness. The level of noise is measured in decibels (dB), and sounds above 85 dB can be harmful over time.CDC/NIOSH, “Noise and Hearing Loss Prevention,” https://www.cdc.gov/niosh/noise/about/noise.html, accessed May 2025.

Noise can also describe data, such as white noise, which lacks meaningful information. Loudspeaker tests often use white noise to assess the frequency response of speakers.Britannica, “White noise,” Britannica.com, https://www.britannica.com/art/white-noise-music, accessed May 2025. In mathematics, noise can also refer to random data, which is often generated without a specific pattern or predictable sequence. This type of noise is useful in fields like cryptography and simulation.BlueGoat Cyber, “Exploring True Randomness in Cryptography and Security,” blog post (Jan 2024), https://bluegoatcyber.com/blog/exploring-true-randomness-in-cryptography-and-security/, accessed May 2025.Menezes, van Oorschot & Vanstone, Handbook of Applied Cryptography, https://cacr.uwaterloo.ca/hac/, accessed May 2025.NIST, “A Statistical Test Suite for Random and Pseudorandom Number Generators for Cryptographic Applications,” NIST SP 800-22 Rev. 1a (April 2010), https://csrc.nist.gov/publications/detail/sp/800-22/rev-1a/final, accessed May 2025.

In electronics, heat causes noise in resistors,Everything RF, “What Is Thermal Noise?” https://www.everythingrf.com/community/what-is-thermal-noise, accessed May 2025.Electronics Notes, “Thermal Noise Calculations,” https://www.electronics-notes.com/articles/basic_concepts/electronic-rf-noise/thermal-noise-calculations-calculator-formulas.php, accessed May 2025. with the amount varying depending on the type of resistor. This is known as thermal noise or Johnson-Nyquist noise.https://pearl-hifi.com/06_Lit_Archive/14_Books_Tech_Papers/Johnson-Nyquist%20Noise Most audio devices are designed to minimize noise production by using components that reduce unwanted signals,Texas Instruments, “Common Noise Issues in Audio Codecs,” Application Report SLAA749, July 2017, https://www.ti.com/lit/SLAA749, accessed May 2025.Texas Instruments, “Noise, TDMA Noise, and Suppression Techniques,” Application Note SNAA033, May 2013, https://www.ti.com/lit/pdf/SNAA033, accessed May 2025. ensuring a clearer sound.

Another type of noise, called background noise, refers to environmental sounds that are not part of the main sound being observed.SVANTEK, “Environmental noise pollution | Measurements | Examples,” https://svantek.com/applications/environmental-noise/, accessed May 2025.International Organization for Standardization, “ISO 1996-1:2016 Acoustics — Description, measurement and assessment of environmental noise — Part 1,” https://standards.iteh.ai/catalog/standards/iso/ab527ade-f16b-407b-994b-e5099bf1bb7b/iso-1996-1-2016, accessed May 2025. This can include sounds like traffic, people talking, or machines operating. In some situations, background noise can be helpful, such as in white noise machines used to aid sleep.Harvard Health, “Can white noise really help you sleep better,” https://www.health.harvard.edu/staying-healthy/can-white-noise-really-help-you-sleep-better, accessed May 2025.

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Category:Sound