What is that extra sound you hear when there are two notes being played as an interval other than a perfect octave or unison?

Answer 1

You could be hearing one or more of several things. As mentioned in the other answers here it may be your ears are picking out overtones - these are additional pitches/frequencies that arise as natural consequences of a vibrating system, like a guitar string or the vibrating air inside a saxophone. You may also be hearing frequencies that are created by the interactions of the two original vibrations - imagine throwing two stones into a pond, you will get two sets of concentric ripples on the water but where the ripples meet or bounce off the edges of the pond they interact and create additional frequencies. The ear will often hear this as a "beating" sound in addition to the original pitches you play. This beating is called heterodying. Additionally, you may be hearing frequency resonances within the room you are sitting in. If the room you are in fits a particular wave length well, that wavelength will resonate and sound louder... and possible make the other things described above. There's a lot going on with sound waves.

Answer 2

If you hear waves between the two notes then the notes are out of tune. If you're hearing extra notes, those tones are part of the overtone series created when two or more notes are played at the same time.

Answer 3

This is an interesting question and one that is important to understand for early learners with guitar.

One of the early challenges for new guitar students is understanding how to tune the instrument. Of course now there are lots of tuners available, but it is still a good idea to teach the manual method of tuning the guitar "with itself". For example, pluck the low E string pressing down on the 5th fret. (this makes an A note). The next string on the guitar is the A string. So, they should match. if they are close but not quite in tune, the overtones or vibrating sounds will be present. This will also occur with the notes played in octaves. These will stop when the instrument becomes in tune. The only way to become proficient with this is to practice. Yep, seems that's always the message in music, right!

Answer 4

Additionally, if you hear something odd when an interval or unison is being played/sung it's usually going to be a wobble, similar to vibrato. Hearing sounds like this in this particular situation means that the two pitches are not in tune with each other. This is why when you listen to a piano tuner work they are often playing octaves of notes, to adjust everything to itself so the piano as a whole is in tune, as opposed to one note being 440 with a tuning device.

Answer 5

The extra note or sound you hear are called "overtones". These occur when two notes are being played that create a resonance within the instrument that produces a frequency that is a multiple of the tones being played. The louder the instrument plays with a drone for example, the louder the overtones get, making it easier to tune the note being played or experimenting with which frequencies occur at different pitches.