The hearing threshold is the minimum sound level a person’s ear is able to detect any sound. For adults - 0 dB is the reference level.
The hearing threshold is normally reduced with age as indicated below:
Room acoustics and acoustic properties, decibel A, B and C, Noise Rating (NR) curves, sound transmission, sound pressure, sound intensity and sound attenuation.
Human physiology, air quality and comfort temperatures, activity and metabolic rates, health effects of carbon monoxide and more.
Sound pressure filters that compensates for the hearing sensed by the human ear.
Maximum recommended sound pressure levels in rooms like kindergartens, auditoriums, libraries, cinemas and more.
The noise level should not exceed certain values to protect public health and welfare.
Maximum daily noise dose level when exposed to periods with different levels.
Comparing Noise Criterion (NC, NCB, RNC) to Noise Rating (NR) and dB(A).
Exposure to noise should be controlled so that it is less than a maximum combination of exposure level and duration.
The Noise Rating (NR) Curve used to determine acceptable indoor environments for hearing preservation, speech communication and annoyance.
Distance and perception of voice.
An introduction to the nature of sound with frequencies, wave-lengths and octaves.
Acoustic power of sound per unit area.
Introduction to decibel, sound power, intensity and pressure.
Sound Pressure is the force of sound on a surface perpendicular to the propagation of sound.