10/11 to 10/13

Pitch - the notes and sounds we hear

Frequency - the proper name for pitch 

Frequency is a measurement of sound waves' vibrations in the air.  The pitch is the resultant sounds and notes we process.

The vibrations of the sound waves are measured in Hertz (Hz).  Hertz is the measurement of cycles per second of a sound wave.

In a sound wave, a cycle is the measurement from the top of the wave to the top of the next wave.

Human hearing has a range from 20 Hz to 20,000 Hz (20 kHz).

In class, we ran through different frequencies to sample high and low frequencies.

We started off with A=440, 440 cycles per second.  The note that sounded was in the medium high range; there are far lower notes and far higher notes than 440.

We divided that number by 2, to sample A=220.  This was a lower version of the A sound.  It was an octave lower in technical terms.

We further divided by 2, sampling 110, 55, and 22.5 Hz.  We went just a bit lower than 20 Hz, but it played out just as expected that our ears hear down to 20 Hz.

Then we multiplied the A=440 by 2 to hear A=880.  Obviously a higher pitch of the same A sound. 

We further multiplied to get 1760.  This tone was not very pleasing to the ear, as it was very high.

Going still further, we tried A=3520, 7040, 14,080.  Prof. Reese was out at 14,080 since as we age, we lose the higher frequencies.

We went up in 1000 increments at 16,000, 17,000, 18,000, 19,000 and 20,000.  At 21,000, no one that heard that frequency.

Different frequencies from 15,000 to 21,000 were the upper limits for our class.

Most music is comfortable in the range of 100 Hz to about 1,000 Hz.  Lower sounds are present in much commercial music,

but it is designed for equipment to handle these low frequencies, and is "felt" as much or more than it is heard.

Higher frequencies above 1,500 are no longer pleasant to the ear in a musical context.