Hearing and psycoacoustics page
- A Survey of Musical Instrument Spectra to 102.4 KHz - there is energy above 20 kHz in some musical instruments, but normal hearing does not hear them Rate this link
- Common Misconceptions about Hearing - paper from Rate this link
- Fletcher-Munson Equal Loudness Curves - What in the world is a Fletcher-Munson equal loudness curve, and why should I care? Humans don't hear all frequencies of sound at the same level. That is, our ears are more sensitive to some frequencies and less sensitive to other frequencies. Not only that, but the sensitivity changes with the sound pressure level (SPL), too. Fletcher-Munson Equal Loudness Curves tell how the ear reacts to different frequencies on different sound levels. Rate this link
- Hearing and perception - operation of the ear Rate this link
- Hearing Impairment FAQ - Mark Rejhon's Frequently Asked Questions about Hearing Impairment! Rate this link
- Human Audio Perception FAQ - short description of loudness curve, Bark scale and critical band Rate this link
- Human Audio Perception Frequently Asked Questions Rate this link
- Noise FAQ - What is noise pollution? Rate this link
- The Binaural Source - Company that sells binaural recordings. Nine Binaural Demo Tracks for Free Downloads plus Search Engine. Rate this link
The human hearing system is an incredibly sensitive sensor system withextensive signal processing in the brain.All sound professional and other people workign with audio system should educate themselves about hearing loss and hearing conservation. The idea that you're responsible for the health and safety of your own ears is common sense. But you may be responsible for somebody else's when you operate anything that makes lots of noise or high level audio signals. You must also understand hearing to understand the operation of hearing to be able to get the good sound on any system. The thing is to understand what is the most important and what is less important in sound is necesary to optimize any sound system. You shoudl play back the important parts best, and if necessary save on those less important ones. The ear can respond to a remarkable range of sound amplitude. (Amplitude corresponds to the quality known as loudness.) The ratio between the threshold of pain and the threshold of sensation is on the order of 130 dB, or ten trillion to one. The judgment of relative sounds is more or less logarithmic, such that a tenfold increase in sound power is described as "twice as loud". The just noticeable difference in loudness varies from 3 dB at the threshold of hearing to an impressive 0.5 dB for loud sounds.Loudness is the psychophysical response to the stimulus of soundpressure, and is a VERY complex response. The subjectiveresponse to the "loudness" of a sound is dependent upon how loudit is to begin with, it's frequency, it's spectral content, thepresence of other, possibly masking sounds, the recent historyof sound perceived (temporal masking) and many other factors.Examples of the complexity: it rquires a MUCH larger differencein power at low frequencies to result in a subjective doublingof loudness than it does at 4 kHz. It requires a largerdifference in power at low sound pressure levels to perceive adoubling than it does at higher SPL'sBut there is no "equation" which relates changes in SPL tope4ceived loudness changes. There are reasonable approximations,and they are not simple. But the often heard "10 dB difference needed for aperceived doubling" is a rul-of-thumb that's reasonably validfor a specific set of circumstances only.
- Equal Loudness Contours - Rate this link
- Fletcher and Munson equal loudness curves Rate this link
- Fletcher Munson Curves - The Fletcher-Munson Curve explains the non-linear response of the human ear, whereby very low and very high frequencies at a given physical intensity are perceived as softer than mid-range frequencies, with 3-4 kHz being the most sensitive frequency range. Rate this link
- Frequency ranges of various equipment and instruments Rate this link
The ear is not equally sensitive to all frequencies, particularly in the low and high frequency ranges.The Fletcher-Munson Curve explains the non-linear response of the human ear , whereby very low and very high frequencies at a given physical intensity are perceived as softer than mid-range frequencies, with 3-4 kHz being the most sensitive frequency range.
- Hearing and Perception - The operation of the ear has two facets: the behavior of the mechanical apparatus and the neurological processing of the information acquired. The mechanics of hearing are straightforward and well understood, but the action of the brain in interpreting sounds is still a matter of dispute among researchers. Rate this link
The operation of the ear has two facets: the behavior of the mechanical apparatus and the neurological processing of the information acquired. The mechanics of hearing are straightforward and well understood, but the action of the brain in interpreting sounds is still a matter of dispute among researchers. The mechanisms of sound interpretation are poorly understood, in fact is not yet clear whether all people interpret sounds in the same way. Most studies in psycho-acoustics deal with the sensitivity and accuracy of hearing. This data was intended for use in medicine and telecommunications, so it reflects the abilities of the average untrained listener.
- Dangerous Decibels: Dancing Until Deaf - high music levels in dance clubs can be dangerous to your hearing Rate this link
- Hearing Losses - Cause and Effect Rate this link
- HEAR Feature Articles - many hearing and hearing damages related articles Rate this link
- NIOSH Hearing Loss Prevention Site Rate this link
- Turn It Up, Eh! Part II - The Horror Continues Rate this link
- What is a decibel, and what is the loudest sound I can listen to before it hurts my ears? Rate this link
- Preventing Hearing Damage When Listening With Headphones - hearing damage from headphones is probably more common than from loudspeakers, because many people exploit the acoustic isolation by listening at higher volumes Rate this link
- Noise Pollution Clearinghouse - non-profit organization with extensive online noise related resources Rate this link
- OSHA Noise and Hearing Conservation - what are tolerable noise levels for workers in USA Rate this link
- Understanding Noise Weighting Curves - Microphones, amplifiers, and recording systems all add some residual noise to the signals passing through them, but the noise generating mechanism and so the spectral content of the noise is different in each case. If noise measurements are to have any real value, allowing fair comparisons of the true noise contributions from different types of equipment, they should give a figure that is representative of what we hear, and the first step towards this is the use of a Weighting Filter , which emphasises some frequencies more than others. Rate this link
Any sound above 85 dB can cause hearing loss, and the loss is related both to the power of the sound as well as the length of exposure. Eight hours of 90-dB sound can cause damage to your ears; any exposure to 140-dB sound causes immediate damage (and causes actual pain).All sound professional and other people workign with audio system should educate themselves about hearing loss and hearing conservation. The idea that you're responsible for the health and safety of your own ears is common sense. But you may be responsible for somebody else's when you operate anything that makes lots of noise or high level audio signals.
Headphones and hearing damages
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