dB HL or "dB hearing level" is used in audiograms as a measure of hearing loss.
dB HL stands for decibel Hearing Level, and dB SPL stands for decibel Sound Pressure Level.
To convert from dB HL (Hearing Level) to dB SPL (Sound Pressure Level), you typically need the specific audiogram for the individual. Once you have the individual's threshold values at different frequencies, you can use them to make the conversion. Each audiometric frequency has a specific conversion factor to convert from dB HL to dB SPL. It is not a direct and consistent conversion across all frequencies.
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.
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).
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).
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.
This pattern indicates a conductive hearing loss. The air-bone gap of 45 dB suggests that there is a problem conducting sound through the middle ear. Bone conduction thresholds are normal, which means the inner ear (cochlea) is functioning properly.
0.00349 hL
There are 100L in a hL
0.08 hL0.08 hL0.08 hL0.08 hL
A Db E Db A Db E Db A Db E Db A Db E Db Ab Db E Db Ab Db E Db Ab Db E Db Ab Db E Db Gb Db Gb(higher) Db Gb Db Gb(higher) Db Gb Db Gb(higher) Db Gb Db Gb(higher) Db fqggbegjg2y7gdsjnjnagydsaytdgtewydtwfe
Because in many statements you use HL as a pointer to memory data, eg: LD B,(HL) SUB A,(HL) LD (HL),E