Confusion between Attenuation and Intesity change

AI Thread Summary
To achieve a sound level of 70 dB SPL, the signal must be adjusted using the attenuator, which reduces the amplitude of the sound signal. Attenuating by 70 dB does not mean the output will be at 70 dB SPL; instead, it refers to the reduction of the signal's intensity. The actual sound level in the air is influenced by the transducer used and the distance from it to the measurement point. It is essential to measure the SPL accurately and then use the attenuator to reach the desired sound level. Understanding the difference between attenuation and sound pressure level is crucial for proper sound manipulation in the research.
mitbhavsar
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Dear All,
I am basically from Bio background and doing research in Insect Physiology as Phd.
Currently I am given a task to generate artificial insect songs using a software.
I did it with 3 v Noise stimuli(1.5 peak to peak) and fed it to amplifier and I heard it on Amplifier.

So now the confusion starts..
I am also given one attenuator which attenuates with the range from -90 db to 0dB.
Now I am suppose to play my song at 70 dB SPL. Does this mean that I have to attenuate my signal at 70dB.?

I mean playing song at 70 dB SPL and attenuating song by 70dB..Are both same things?
PLease help me..
Thank you in Advance
 
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The sound level in the air will depend on the transducer (loudspeaker, etc) you use to play the sound, and the distance between the transducer and the measurement position.

You need to measure the SPL, and use the attenuator to adjust it to 70dB.
 
Adding to AlephZero's measuring of the SPL,

http://www.animations.physics.unsw.edu.au/waves-sound/quantifying/ has some good information that may help.

e.g., these topics are from the What is a decibel? link.

Definition and examples
Sound files to show the size of a decibel
Standard reference levels ("absolute" sound level)
Logarithmic response, psychophysical measures, sones and phons
The filters used for dB(A) and dB(C)
Recording level and decibels (dBV and dBm)
Intensity, radiation and dB
Pressure, intensity and specific impedance
dBi and anisotropic radiation
Example problems using dB for amplifier gain, speaker power, hearing sensitivity etc.
Occupational health and safety and the law
Related pages
What is a logarithm? A brief introduction.
 

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