Sound Intensity

B Block worked on their Tones, Vowels and Telephones lab to see how single and multiple sound waves behave. A tuning fork was used to demonstrate a pure tone, then bashed harder to produce overtones. The original sine curve became far more complex, due to the interference among the various tones and the FFT graph could be used to ferret out the combating frequencies. Vowel sounds and the dual-tone system for the DTMF phone tones was also explored. Tomorrow, we jump into properties of sound and also touch on the concept of Doppler Effect.

C Block reviewed yesterday's sound lab and started in with basic sound properties today. We reminded ourselves that sound was a longitudinal, mechanical wave that has properties identical to the source vibration. We took on the idea of hearing and vocalization ranges and uses for ultrasound that we picked up from observing the animal kingdom. Tomorrow, we add how the medium affects speed of sound and the Doppler Effect to our bag of tricks.

E Block spent time discussing sound intensity. Though the basic definition is presented with the unit W/m², which indicates the inverse square relationship between distance and intensity, the decibel scale was also introduced as was the relationship between intensity and wave amplitude. Tomorrow, we hit forced vibrations and resonance.

F Block also discussed sound intensity after reviewing basic wave properties. The inverse-square relationship between sound intensity and distance from a source was explored and the decibel scale was described and related to common examples to give students a benchmark from which to evaluate sound level. Sound can affect mood and health, not only hearing and we discussed some of thee effects in class, also. Tomorrow, we'll take on forced vibrations and resonance.