S302, Kewley-Port 10/14/07

Homework 8

Resonance & Filters

1. Draw a waveform and spectrum for a pulse with a duration duration of 1 ms.

 

 

 

2. The SNR is measured at -10 dB for a particular tone in white noise. If the level of tone is 65 dB IL, what is the level of the noise?  How easy will it be to perceive the tone (interpret SNR)?

 

3. The sound at 10 cm from a tuning fork with a frequency of 256 Hz is measured as 66 dB SPL. The tuning fork then touches a box which begins to resonate quite clearly.

a) Explain what frequency will the box vibrate at?

 

b) Explain whether the sound at 10 cm from the box can have a higher sound pressure level after it touches the box.

 

c) Explain the role of impedance of the box relative to the tuning fork.

 

4. Look at Fig. 6-3. Define the meaning of the following terms that apply to Fig. 6-3:

a) resonance curve

b) filter

c) system transfer function

5. Explain what componants of impedance affect the natural resonance of a system.