I was hoping I could crowd source some understanding.
Im interested in understanding the measuring of sound pitch. From what I've been able to gather thus far- sounds are waves of air pressure and can be measured by a microphone (a tool which converts the vibrations of air waves into electrical energy). The signal recieved from a microphone represents the amount of air being displaced relative to the capacity for which the microphone can measure and the microphones resting state.
So from the information above, I can reasonably understand that if hypothetically something were to disturb the air in a given space, that the particles of air adjacent to the source would move away from the origin in a wave like pattern; assuming the microphone was in proximity and the air pressure generated was strong enough, the microphone would ouput an electrical analog signal; and that if something disturbed the air in a given space continually over a peroid of time then each disturbance would generate a set of particles which moved away in wave like patterns; Those sets of waves would reach the microphone in succession, each wave generating a signal within the microphone. The microphone signals could be recorded to show their change in value in relation to time. Given the time frame of a single second, if someone were to count all the waves that appeared in a sample they should be able to calculate the frequency of that sample.
So if my interpretation thus far is accurate then I should be able to construct the example that assuming there's a never ending vibrating string that creates a clean sine wave of the musical note 'A'(440hz) then subsequently, there would be disturbed sets of air partilces moving away from that string in wave like patterns at a rate of 440 sets of air particles per second. The displaced air would travel through space until it reached a microphone at which point, each wave would be converted into an electrical signal and then recorded. After the sound was recorded, someone should be able to observe the recordings and calculate the number of waves in a one second sample. They would find 440 waves and conclude that the pitch of the source was at 440hz and that the noise sounded like the musical note 'A'.
Alternatively, and here's where I think my understanding breaks down- if the sound is not clean or repeatitive in nature then how is the frequency (pitch) changed? How would a non uniform waveform sound in comparison to a uniform waveform when both samples have the same number of waves for a given second but look very geometrically different?
Also, determining the pitch of a sound whose duration is less than a second? Like a single drum beat and how the pitch would change as the number of drum beats increased into a seemingly continuous tone.
Thank you very much for your time and awareness. I highly appreciate any input.