When dealing with sound intensities and decibel levels, a convenient approximation (accurate to 2 significant figures) is: For every doubling of the intensity, the decibel level increases by 3.0. Suppose the sound level at some location is 85 dB. Find the decibel levels if the sound intensity is increased by factors of (a) 2.0, (b) 4.0, (c) 8.0, and (d) 16.

Problem 4. A point source emits sound waves uniformly in all directions. At distance 90.0 m from the source the sound intensity level is 15 dB. At what distance from the source is the sound intensity level 35 dB?

A very noisy chain saw operated by a tree surgeon emits a total acoustic power of 34.0 W uniformly in all directions. (A) At what distance from the source is the sound level equal to 110 dB? Express your answer in meters. (B) At what distance from the source is the sound level equal to 58 dB? Express your answer in kilometers.

What is the decibel level of a sound that has an intensity of 10.4 x 10-5 W/m2? Assume the standard dB level scale where the reference intensity is 1 x 10-12 W/m2

The higher frequency limit for human hearing is 23.9  kHz. If the air temperature is 12.2 °C, the corresponding wavelength (mm; millimeter) of the sound is:

12 gives the loudness of sound L (in dB) based on the intensity of sound I (in W/m²). The value I = 10 The formula L=10 log threshold for hearing for midfrequency sounds. Hearing impairment is often measured according to the minimal sound level (in dB) detected by an individual for sounds at various frequencies. For one frequency, the table depicts the level of hearing impairment. Category Mild Moderate Moderately severe Severe Profound Loudness (dB) 26≤L≤40 41≤L≤55 56≤L≤70 71 ≤L≤90 L>90 W/m is the minimal (a) If the minimum intensity heard by an individual is 9421.4 x 108 W/m², determine if the individual has a hearing impairment. Round to the nearest tenth. (b) If the minimum loudness of sound detected by an individual is 40 dB, determine the corresponding intensity of sound.

A noisy factory machine produces a sound intensity of 1.00 x 10-5 W/m2 when measured 10 m from the machine. Assume that the sound spreads out uniformly into 3 dimensions for this set of questions. What is the sound power output of the machine? (Give your answer in mW.) What is the decibel level of the machine at 10 m? At what distance is the decibel level equal to 55 dB? (Give your answer in m.)

The difference in two sound levels, β1 and β2, in decibels (dB), is given by the logarithmic equationβ2 − β1 = 10 log ( I2/,I1)   where I2/I1 is the ratio of their intensities.  a) The sound level of a jet at take off is 140 dB, while the level of a normal conversation is 50 dB. What is the ratio of the intensities of the sound level of the jet versus the level of normal conversation? b) What is the loudness of a jackhammer (in use) if it is known that this sound has anintensity 10 times that of sound due to heavy city traffic (90 dB)?

Problem #8: The noise from a grinder in a factory is 32000 times more powerful than the noise from a dishwasher. By how many decibels is the factory noise greater than the dishwasher noise? Problem #9: A loud sound is 90 dB. When the sound is reduced to 5% of its original intensity, what is the decibel level? Problem #10: At a rock concert, a dB meter registered 130 dB when placed 2.8m in front of a loudspeaker on the stage. What is the power output of the speaker, assuming uniform spherical spreading of the sound and neglecting absorption in air? Problem #11: By how many decibels do you reduce the sound intensity level due to a source of sound if you quadruple your distance from it? Assume that the waves expand spherically.

The intensity level in decibels is defined as 10 log10(I/I0), where I0 is a reference intensity equal to the human threshold of hearing, 10–12 W/m2. What is the intensity of the threshold of pain, 120 decibels? answer is : 10° W/m2   I'm not sure how they got this answer