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).
For frequency ranges, we can hear from 20 Hz to 20000 Hz (20 kHz). This is due to a limit on the length of our cochlear basalar membrane. If it were longer, we may be able to hear a greater range. For loudness, using a standard pressure level (SPL) absolute value system, we can hear at soft as 20 dB SPL (just audible whisper) to about 120-140 dB SPL (which will begin to cause hearing loss and irreversible damage).
Increase = 10 log(B/A) dB = 10 log (3000/1) = 10 ( 3.47712) = 34.8 dB (rounded)
181.9 DB by Craig Butler
A avalanche can range from 100 dB to 180 dB
Ag, Db and Xe are chemical elements.
dB HL stands for decibel Hearing Level, and dB SPL stands for decibel Sound Pressure Level.
IL is not equal to SPL. Actually SPL = IL + 0.16dB.
The sensation level is measured in decibels. It is frequency specific and starts at 0 dB SL (sensation level) where 0 dB SL is the softest the patient can here a specific frequency. This means that the SL will be different for different people. Everyone's SL will start at 0 but my SL at 1000 Hz may be at 23 db IL and another's may be at 54 db IL.Put more simply, dB SL is the difference between a person's threshold of hearing and the presentation level of a stimulus. If a person's speech reception threshold (SRT) is 10 dB on an audiometer (dB HL) and you present a speech stimulus to them at 50 dB HL on the audiometer, their sensation level would be derived thus: 50 dB (presentation level) minus 10 dB (threshold), which equals a sensation level of 40 dB SL. This is also the procedure for a frequency-specific stimulus (e.g. pure tones): subtract the audiometric threshold (dB HL) from the supra-threshold presentation level (dB HL) and the difference is the sensation level (dB SL).
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
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".
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.
130 dB is an SPL commonly considered to be the threshold of pain. Between 120 and 140. http://ccrma-www.stanford.edu/~jos/st/DB_SPL.html
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
If you mean the sound pressure level that causes pain, it is about 120 dB SPL.
About 20 dB SPL (sound pressure level).
about 40 db about 40 db
The ear drums feel the sound pressure difference of the factor 100; that is 20 log 100 = 40 dB. The microphone at a sound pressure level meter (SPL) can measure that.