dB SPL is a comparison of a sound level to what was thought to be the threshold of hearing, although today it is known that the value was too high. dB HL is a measure of hearing loss - a comparison of a subjects hearing compared to a 'normal' standard. As they are measure different things a direct comparison is not possible.
The differences between dB HL and dB SPL, arise from isophonic curves. There is no direct (linear) formula to convert this but a set of formulas. For different frequencies, different values should be added. For eg., at 1kHz you can state that 0dB HL is around 2dB SPL while at 250Hz, 0dB HL is 12 dB SPL.
db HL = db Hearing Level
db SPL = db Sound Pressure Level
Simple, just subtract 20 from the SPL, and that gives you the HL.
-M.A
IL is not equal to SPL. Actually SPL = IL + 0.16dB.
About 20 dB SPL (sound pressure level).
The "SL" in dB SL stands for "Sensation Level". The "HL" in dB HL stands for "Hearing Level". The difference between them is that dB SL is based on the hearing ability of an individual test subject, and dB HL is based on the hearing ability of an entire population of test subjects. 0 dB SL is the minimum level at which the test subject can hear a stimulus, usually a tone pip. The actual level will vary with frequency. If we refer to a level of, say, 40 dB SL, we mean a sound that is 40 decibels above a test subject's threshold of hearing. The dB HL scale is the mean dB SL of a large population (theoretically the world-population) of *normal hearing* people. They measured frequency-specific thresholds for alot of people, and averaged them to give the dB HL scale. Finally, dB nHL stands for "normalised hearing level". This is the same concept as dB HL, except the number of test subjects contributing to the average is smaller. It is standard practice for a Hearing Clinic to establish their own dB nHL scale based on all the normal-hearing test subjects they have had access to. This allows a clinic to ensure that the scale they use is correctly calibrated to their test equipment.
You cannot convert DBi to DB because they are not related. DBi is only for decibels in an isotropic radiator, while DB is only for decibels in a dipole antenna.
The ear drums are moved by the sound pressure deviations only. Therefore don't ask for sound intensity. Sound pressure is measured by an SPL meter. Very loud noise is aching. The "threshold of pain" has the value of about 130 dB Sound Pressure Level (SPL). "Permitted Exposure Time Guidelines - SPL" Sound pressure level Lp and permissible exposure time t: 115 dB = 0.46875 minutes (~30 sec) 112 dB = 0.9375 minutes (~1 min) 109 dB = 1.875 minutes (< 2 min) 106 dB = 3.75 minutes (< 4 min) 103 dB = 7.5 minutes 100 dB = 15 minutes 97 dB = 30 minutes 94 dB = 1 hour 91 dB = 2 hours 88 dB = 4 hours 85 dB = 8 hours 82 dB = 16 hours Lower dBs are said to be harmless There are accepted standards for recommended permissible exposure time for continuous time weighted average noise, according to NIOSH (National Institute for Occupational Safety and Health) and CDC (Centers for Disease Control and Prevention) in 2002. For every 3 dBs over 85 dB, the permissible exposure time before possible damage can occur is cut in half.
dB HL stands for decibel Hearing Level, and dB SPL stands for decibel Sound Pressure Level.
There are several types of dB. dB SPL are decibels measuring sound pressure levels. There is an accepted reference point of 0 dB SPL which equals 20 micropascals = 2 × 10-5 pascals. dB SL are decibels measuring a signal relative to an individuals auditory threshold. For example, if a person's minimum threshold is 30 dB HL (yet another type of decibel measuring how much worse a person's hearing is based on a referential dB level) and a signal is at 40 dB HL, the sensation level of this signal to this individual is 10 db SL (40 dB - 30 dB = 10 dB SL).
IL is not equal to SPL. Actually SPL = IL + 0.16dB.
This seems like a question from an electrical course, and is probably best answered by referring to your course materials. It's your test question, not ours, and there won't always be someone else to ask for the answer. Earn your diploma.
It depends on how loud it is. In hearing, the threshold of pain is the sound pressure or sound pressure level beyond which sound becomes unbearable for a human listener. This threshold varies only slightly with frequency. Different values for the threshold of pain are found in the literature: Here are some sound pressure levels SPL in dB and the sound pressure in pascals of the sensed possible threshold of pain: SPL 120 dB = 20 Pa SPL 130 dB = 63 Pa SPL 134 dB =100 Pa SPL 137.5 dB =150 Pa SPL 140 dB =200 Pa
The usual soundlevel can be between 0 dB SPL = 20 µPa (threshold of hearing) up to 130 dB SPL (threshold of pain). An average sound level could be at 85 dB SPL. Scroll down to related links and look at "Average sound pressure levels".
If you mean the sound pressure level that causes pain, it is about 120 dB SPL.
About 20 dB SPL (sound pressure level).
How do I convert a .db file?
The "SL" in dB SL stands for "Sensation Level". The "HL" in dB HL stands for "Hearing Level". The difference between them is that dB SL is based on the hearing ability of an individual test subject, and dB HL is based on the hearing ability of an entire population of test subjects. 0 dB SL is the minimum level at which the test subject can hear a stimulus, usually a tone pip. The actual level will vary with frequency. If we refer to a level of, say, 40 dB SL, we mean a sound that is 40 decibels above a test subject's threshold of hearing. The dB HL scale is the mean dB SL of a large population (theoretically the world-population) of *normal hearing* people. They measured frequency-specific thresholds for alot of people, and averaged them to give the dB HL scale. Finally, dB nHL stands for "normalised hearing level". This is the same concept as dB HL, except the number of test subjects contributing to the average is smaller. It is standard practice for a Hearing Clinic to establish their own dB nHL scale based on all the normal-hearing test subjects they have had access to. This allows a clinic to ensure that the scale they use is correctly calibrated to their test equipment.
32.5 mL = _____ hL
dB HL stands for decibels Hearing Level and is a unit used to measure the relative loudness perception for an individual with hearing loss. It represents the volume level of sounds that an average person with normal hearing can hear at a given frequency, serving as a reference point for audiologists to determine the extent of a person's hearing loss.