Frequency range for instruments
These for obvious reasons are acoustic instruments and unamplified. The frequency refers to fundamental tones only. To give an extreme example a massive church bell such as ‘Big Ben’ will produce low frequencies you can feel in your gut and yet the harmonics will go way beyond the range of human hearing.
Interesting that a sound system will produce almost all the musical fundamentals of an orchestra without bothering the tweeter… thank Heaven for harmonics!
Sound pressure levels
This is a simple scale based on every day observations similar to the beaufort wind scale. Remember that the decibel is a log scale so that a 3dB increase is a doubling of the actual sound energy, 10dB represents a ten fold increase. However to complicate matters the human ear is not linear and perceives a 10 dB increase as a very approximate doubling of volume.
Sound level (dB) approximate observed equivalent.
Sound proof room, threshold of hearing.
Rustle of leaves in a breeze.
Conversation at home
Typical outside conversation
Noise in a large shop (no musac ;-))
Noisy office with typing (you need to raise your voice)
Underground railway train passing
Pneumatic Drill at 3 m
Prop aircraft taking off
Jet aircraft taking off – threshold of pain.
Remember that anything over 80 dB can damage hearing over time.
Audible intensity of musical instruments
This is a guide to the sort of sound pressure levels acoustic instruments produce unamplified. No distances were given but I’d guess pretty close – a couple of metres perhaps.