Sources and pathways of noise penetration
Noise pollution in modern cities is a major hygienic issue. People whose homes are located along major transport routes suffer from it the most.
Noise enters an apartment through two pathways:
- From outside: through windows, gaps in frames, and poorly soundproofed walls. Street noise is mainly generated by traffic (trucks, trams, aviation), industrial facilities, and violations of "sound discipline" (car horns, loud music from windows).
- From inside: from ground-floor shops, workshops, and elevators built into the building. Indoor noise arises from thin interior partitions, household appliances, loud conversations, and radio broadcasting.
Noise regulation and reduction
Sound intensity is measured in relative logarithmic units — decibels (dB). For a comfortable and safe stay in an apartment, clear hygienic standards have been established:
- During the daytime (07:00–23:00) — 40–55 dBA.
- During nighttime (23:00–07:00) — 30–45 dBA.
Combating noise requires a comprehensive approach. At the city level, this includes moving industrial zones outside residential areas, greening streets, and using sound-absorbing coatings for facades and roads. In everyday life, thick curtains, carpets, and soft furniture help reduce sound levels.
Impact of noise on the body
Sounds are essential for human communication and orientation, but prolonged exposure to intense noise causes systemic pathological changes.
High background noise leads to fatigue, decreased attention, and increased nervous excitability. Elevated blood pressure is observed in the cardiovascular system, while inhibition of motor and secretory functions occurs in the gastrointestinal tract.
It has been proven that prolonged exposure to domestic and street noise contributes to the development of:
- Hypertension;
- Nervous system disorders;
- Peptic ulcer disease of the stomach and duodenum.
Effect of night noise on sleep
Silence during sleep is vital. According to the teachings of I.P. Pavlov, sleep is a process of irradiated inhibition in the cerebral cortex. Any external stimulus, such as noise, creates foci of excitation and disrupts the inhibition process.
As a result, sleep becomes superficial and inadequate, failing to allow the central nervous system to restore its functions.
Briefly: answers to topical questions
What specific changes in the organ of Corti are caused by prolonged exposure to intense noise?
Prolonged exposure to intense noise causes degeneration of the organ of Corti. This specific action leads to hearing loss, which with prolonged exposure can progress to occupational deafness. In addition, the specific reaction of the auditory apparatus includes:
- Adaptation of the auditory system — manifests as an increase in hearing sensitivity thresholds.
- Auditory fatigue — a condition where sensitivity thresholds slowly return to baseline levels.
If noise exposure continues, elevated thresholds persist by the start of the next work shift.
According to what physical parameters, besides sound intensity, is noise classified and regulated in hygiene?
In addition to intensity, noise is characterized by frequency and temporal parameters.
- Frequency is measured in Hertz (Hz). By frequency, acoustic vibrations are divided into infrasound (less than 16 Hz), audible sound waves (16 Hz–20 kHz), and ultrasound (above 20 kHz).
- Temporal characteristics: noise is classified into continuous, intermittent, and impulse noise; impulse noises consist of one or more sound signals, each lasting less than 1 second.
To regulate continuous noise, sound pressure levels in decibels in octave bands with geometric mean frequencies of 31.5, 63, 125, 250, 1000, 2000, 4000, and 8000 Hz are used. A single-number characteristic is also applied — the sound level in dB(A), which represents a weighted average of the frequency characteristics of sound pressure.
Class and exam questions
What is a decibel (dB)?
Sound intensity is expressed in decibels (dB). This is a conditional logarithmic value showing how much a sound exceeds the hearing threshold (0 dB).
What diseases are provoked by constant noise?
Chronic noise exposure contributes to the development of hypertension, peptic ulcer disease of the stomach and duodenum, and various nervous system disorders.
What are the noise standards for residential premises?
During the day (07:00 to 23:00), the noise level must not exceed 40–55 dBA, and at night (23:00 to 07:00) — 30–45 dBA.
What else to study on this topic
- Indoor air pollution (chemical and microbial)
- Toxic emissions from polymer construction materials
- Impact of gas combustion and tobacco smoke on the microclimate
- Indoor allergens and house dust mites
- Sick building syndrome
Master the entire topic in the "Hygiene" course
This is a summary. The course covers everything tested in classes and exams.
- Complete study guide on "Indoor Noise" and 530 more pages on the subject
- Assignments and quizzes after every topic — just like in a colloquium
- AI tutor answers questions on the topic anytime
- 95 video lessons for the subject
Other topics in the section "Chapter 4. Ecological and hygienic problems of populated areas and housing"
Prepared by WhiteCoat Pro faculty in accordance with the medical school curriculum. For educational purposes only.