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Sound measurement apps can help one find out how loud sounds are. If not measuring the sound levels, a good rule of thumb is that sounds are potentially hazardous if it is necessary to speak in a raised voice to be heard by someone an arm's length away. Moving away from the sound or using hearing protection are approaches to reduce exposure levels.
Ear hair is the terminal hair arising from folliculary cartilage inside the external auditory meatus in humans. [1] In its broader sense, ear hair may also include the fine vellus hair covering much of the ear, particularly at the prominent parts of the anterior ear, or even the abnormal hair growth as seen in hypertrichosis and hirsutism ...
The stereocilia (hair cells) of the inner ear can become subjected to bending from loud noises. Because they are not regeneratable in humans, any major damage or loss of these hair cells leads to permanent hearing impairment and other hearing-related diseases. [2] Outer hair cells serve as acoustic amplifiers for stimulation of the inner hair ...
These hairs line the cochlea from base to apex, and the part stimulated and the intensity of stimulation gives an indication of the nature of the sound. Information gathered from the hair cells is sent via the auditory nerve for processing in the brain. The commonly stated range of human hearing is 20 to 20,000 Hz.
The horizontal axis shows frequency in Hertz. In acoustics, loudness is the subjective perception of sound pressure.More formally, it is defined as the "attribute of auditory sensation in terms of which sounds can be ordered on a scale extending from quiet to loud". [1]
Note: The complete anatomy of the human ear is extensive, and can be divided into the inner ear and outer ear. The remainder of this article mainly references the cochlea, outer hair cells, and organ of Corti. In general, structural damages to any anatomical part of the human ear can cause hearing-related problems.
NIHL can be either permanent or temporary, called a threshold shift. Unsafe levels of noise can be as little as 70 dB (about twice as loud as normal conversation) if there is prolonged (24-hour) or continuous exposure. 125 dB (a loud rock concert is ~120 dB) is the pain level; sounds above this level cause instant and permanent ear damage.
The frequency of a sound is defined as the number of repetitions of its waveform per second, and is measured in hertz; frequency is inversely proportional to wavelength (in a medium of uniform propagation velocity, such as sound in air). The wavelength of a sound is the distance between any two consecutive matching points on the waveform.