Search results
Results From The WOW.Com Content Network
Traumatic noise exposure can happen at work (e.g., loud machinery), at play (e.g., loud sporting events, concerts, recreational activities), and/or by accident (e.g., a backfiring engine.) Noise induced hearing loss is sometimes unilateral and typically causes patients to lose hearing around the frequency of the triggering sound trauma. [17]
Cargo ships generate high levels of noise due to propellers and diesel engines. [79] [80] This noise pollution significantly raises the low-frequency ambient noise levels above those caused by wind. [81] Animals such as whales that depend on sound for communication can be affected by this noise in various ways.
An audio frequency or audible frequency (AF) is a periodic vibration whose frequency is audible to the average human. The SI unit of frequency is the hertz (Hz). It is the property of sound that most determines pitch. [1] The generally accepted standard hearing range for humans is 20 to 20,000 Hz.
Hearing loss due to chemicals starts in the high frequency range and is irreversible. It damages the cochlea with lesions and degrades central portions of the auditory system . [ 72 ] For some ototoxic chemical exposures, particularly styrene, [ 73 ] the risk of hearing loss can be higher than being exposed to noise alone.
By listening to broadband noise at soft levels for a disciplined period of time each day, some patients can rebuild (i.e., re-establish) their tolerances to sound. [ 2 ] [ 47 ] [ 48 ] [ 49 ] More research is needed on the efficacy of sound therapy techniques when hyperacusis is the primary complaint, rather than a secondary symptom, indicating ...
The second component is known as "distortion" or "clarity loss" due to selective frequency loss. [8] Consonants, due to their higher frequency, are typically affected first. [7] For example, the sounds "s" and "t" are often difficult to hear for those with hearing loss, affecting clarity of speech. [9] NIHL can affect either one or both ears.
[5] [6] Age affects high frequencies more than low, and men more than women. One early consequence is that even young adults may lose the ability to hear very high frequency tones above 15 or 16 kHz. [3] Despite this, age-related hearing loss may only become noticeable later in life.
The first research on the topic of how the ear hears different frequencies at different levels was conducted by Fletcher and Munson in 1933. Until recently, it was common to see the term Fletcher–Munson used to refer to equal-loudness contours generally, even though a re-determination was carried out by Robinson and Dadson in 1956, which became the basis for an ISO 226 standard.