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I have a few questions for the group:
1) How do you add two different decibel levels?
Must you convert it to intensity first?
For example, 65 dB + 80 dB
? 145 dB.
delta B = 10log(80/65) =
0.9, and so the answer is 65.9 dB?
2) If a car sounds a horn. If you hear 450 Hz as it approaches and 350Hz
as it recedes, the actual frequency is about 394 Hz (not 400 Hz).the
Conceptually, why isn't the Doppler effect result symmetric for when
sound (or observer) is approaching/receding the observer (sound)?
3) All musical instruments produce overtones (harmonics) except tuningproduce
forks and some electronic pianos. How can the human vocal chords
pure tones? Living things are both delicate and complex, yet it iseasy to
sing into a microphone and see a nice sine wave on an oscilloscope.