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S3 - Acoustics
Pitch, Loudness and Timbre
Question | Answer |
---|---|
What is the pitch interval equation? | Change in pitch= (1200/log2)log(f2/f1) Change in pitch= 3986log(f2/f1) |
What happens when a harmonic series is identified? | The brain identifies a single musical tone with pitch equal to the fundamental |
When does 'fusion' occur? | When the harmonic components are incomplete or slightly out of tune. |
What is the dominance region? | Frequencies between 500-2000Hz that are given particular weight by the brain in assessing the pitch. |
What happens if no harmonic series is identified? | Harmonic components are heard separately. |
Define intensity. | Intensity is the energy carried across an area of 1m^2 by the wave each second (measured in Wb/m-2) where I is proportional to the power. |
Define Sound Power. | Sound Power is the total amount of energy radiated per second (measured in W). |
What is an 'isotropic' sound? | An isotropic sound is a sound that radiates uniformly in all directions. |
What is the relationship of intensity and distance? | The intensity is inversely proportional to the square of the distance. |
What is the intensity ratio in decibels? | I(dB) = 10log(I2/I1) OR I(dB) = 10log(I1/I0) where I0 is the standard relative intensity I0=1x10-12 Wm-2 |
What is the musical dynamic range? | ppp at 30dB and fff at 100dB where there is a 10dB gap per dynamic marking. |
What do equal loudness contours illustrate? | The variation of the sensitivity of the area. |
What is the 'threshold of audibility'? | This is the intensity level for a just audible sound e.g. a whisper (at 30dB) |
What does 'A-weighting' mean? | Setting a sound level meter so that to mimic the human sensitivity of the ear. |
At what volume does sound cause ear damage? | 100dB |
How can timbre be described? | By its waveform and frequency spectrum. |
What is a 'formant'? | A formant is a region of frequency in which the average spectrum is likely to peak. |
What is the 'onset transient'? | The onset transient is important in giving the sound its characteristic timbre (information rich). |