The World's most unanswered science questions:
Sound

Everything to do with Sound - waves, transmission and even music - is covered on this page. Before diving straight into the questions, here's a quick table showing the special symbols and what they mean.


This symbol means that the question is difficult to find out in practise. However, through lateral thinking and common sense, an answer is possible. This symbol means that the question is nigh-on impossible to verify by experiment alone. However, through lateral thinking and common sense, an answer is possible.
This symbol means that the question is delving into the theoretical realm and is once again difficult to test. The answer/s are possibly right - but not guaranteed! The ultimate! Questions with this symbol push the boundaries of theoretical knowledge - and are nigh on impossible to verify by experiment. Any answers are based on our current understanding of the universe - and thus are subject to error.

Anchors:

  • Planes and sudden over-head sound
  • The tinny earphones conundrum
  • A perfect melody?
  • How does something sound in...
  • The stereo effect and gauging direction
  • The perfect 'sound-o-meter'
  • Sound absorption materials
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  • Loss of sound energy through heat
  • Deadly sound frequencies
  • The decibel and its measurement
  • Googleplex of volume
  • What is twice as loud?
  • Why are there 12 notes to the octave?
  • Heat and micro sound waves
    		•


    Planes and sudden over-head sound
    Q: When a plane is coming from a far distance, one moment you can't hear it, the next, the engine suddenly becomes heard. Why not a gradual increase in volume? Is should fade in gradually - surely?
    The tinny earphones conundrum
    Q: When you hear someone listening to music via headphones, you can't hear any bass - only treble. One would think though that the bass would be louder (since the treble should be absorbed more by the earphones' plastic etc). Why then are ear/head phones so 'tinny' from a distance?
    A perfect melody?
    Q: In music, is there such thing as a perfect melody, rhythm or chord sequence?
    For a further breakdown of whether music can be rated outside of human opinion, visit the Aesthetics of music page.
    How does something sound in...
    Q: What difference would be made to the sound we hear if:
    A: The air pressure was twice as great?
    B: The air pressure was half as great?
    C: The temperature of the air was just above absolute zero?
    The stereo effect and gauging direction
    Q: Is the reason why one can recognise from what direction sound is coming from because sound reaches one ear fractionally before the other? What difference(s) would just one ear make?
    The perfect 'sound-ometer'
    Q: Is there an instrument that can measure the level of sound and display the results in a kind of disc which gives information on the intensity, direction and perhaps distance in a either a digital or graphical format?.
    For example, the east edge of the disc would glow brighter if sound were coming from that direction. Maybe even a spherical version of this could be made. Again, the data could be represented graphically with glowing "mountain ranges" appearing on the surface of the sphere.
    Sound absorption materials
    Q: What material reflects sound the least and most?
    What material absorbs sound the least and most?
    Give comparisons with other everyday materials (and diamond)
    Loss of sound energy through heat
    Q: A very minuscule (but no doubt there) amount of sound is converted into heat when travelling through air. What percentage exactly?
    Deadly sound frequencies
    Q: At the same amplitude, which frequency of sound is least and most harmful to the ears? Would these levels be proportional to the apparent 'loudness' to our ears?
    What's the deal with the alleged 'dangerous' frequency at approximately 7 Hertz?
    The decibel and its measurement
    Q: If a particular measure of 'loudness' is 50 decibels, is that referring to the source's actual output or from what you hear standing at a particular distance?
    What would be the name of measurement for both of these types of measurement (decibels and...)?
    Googleplex of volume
    (Yes I know it should be spelt "Googolplex" :-P )
    Q: Is there a theoretical limit to how loud something can be (in physical and perceptional terms)?