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3.AUD-Decibels
Audiology SLP314
Question | Answer |
---|---|
Sound amplitude is expressed in what? | Pressure. |
Pascals (Pa) are units of what? | (Sound) pressure. |
Decibels are what kind of scale? | Logarithmic (ratio). It compares two pressures. |
What is the formula for dBs? | dB = 20 log (P1/P2) Take the logarithm (base 10) of the ratio of two sound pressures and multiply it by 20. |
What is the reference for measuring a single sound (zero point)? | 20 μPa. The lowest sound pressure humans can hear. |
How are sounds measured using the standard reference denoted? | dB SPL (sound pressure level) |
What is the maximum tolerable sound pressure for humans? | 140 dB SPL. |
How many dBs SPL is 20 μPa? | 0. |
What does a sound level meter do? | It measures sound pressure and converts to dB SPL scale. |
What's the relationship between intensity and loudness? | Loudness is a subjective perception of intensity. |
What is a hearing threshold? | The lowest point one can hear. |
What shape is the human audibility curve and why? | Banana-shaped, because the outer and middle ears transmit middle frequencies more efficiently than low and high frequencies. |