Acoustics & Decibels: Sound Levels, Adding Sources & Noise Exposure

What you'll build

What you will be able to do

Each lab ends with a concrete result that you build yourself and the checker confirms, cell by cell.

• Turn eight RMS sound pressures into decibels with 20·LOG10(p/p₀), go back from a level to pascals and count the sources at or above 85 dB.
• Add six machine levels the energy way, see what switching one machine off does, and subtract the background noise from a measurement.
• Calculate how a generator's level falls with distance as a point source and as a line source, chart both, and find the distance where the level meets a night limit.
• Time-weight a press operator's six activities into an energy dose, calculate the shift Leq and the 8-hour exposure LEX,8h, and find which activity causes most of the dose.
• Calculate how long a worker may stay at eight levels under a 3 dB and a 5 dB halving rule and turn two hours at 95 dB(A) into a daily dose.
• Calculate a music room's volume, the absorption of five surfaces and the reverberation time RT60 with the Sabine formula.
• Compare three acoustic treatments for the music room: added absorption, the new RT60 and the drop in reverberant level, and pick the option that meets the 0.8 s target on its own.
• Convert eight octave-band frequencies into wavelength and period, chart wavelength against frequency, and correct the speed of sound for temperature.