1) If brown noise has an intensity of 50 dB (re: 10-12 ) W/m2) at 100 Hz, what is the intensity in dB at 300 Hz? Hint: because octaves are on a log2 scale, you should find a log2 calculator. Show all equations used in your calculations.

2) As we will learn in Part II of the course, sound energy in the ear canal enters the middle ear via the ear drum, travels through three connecting ossicles (bones) in the middle ear, and then enters the inner ear via a thin membrane called the oval window. The diameter of the oval window is ~4 times shorter than the diameter of the ear drum. If a 40 dB SPL sound enters the middle ear, then what is the sound pressure level at the oval window? Assume sound energy is neither absorbed by the ear drum/ossicles nor lost as heat during transmission, and that the ear drum and oval window are both circular in shape. You can also ignore the amplification by the tympanic membrane and middle ear ossicle lever mechanism. (Hint: first calculate the absolute sound pressure in Pa)

\fSPL oval window = 40 + 20 1 legit 6408 db