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Topic: What's the correlation between sampling rate and audio frequency (audio pitch)? (Read 468 times) previous topic - next topic
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What's the correlation between sampling rate and audio frequency (audio pitch)?

Hello,
I am trying to understand how digital audio works, and I've read that to convert and analog signal to a digital one, you need to scan the signal. And the smaller the time period between a sample is, the higher the sample rate and the higher the audio quality. But why exactly does this have effects on the maximum frequency? Doesn't it just have an effect on the detail of the audio, so how much detail is captured?

Re: What's the correlation between sampling rate and audio frequency (audio pitch)?

Reply #1
Sampling rate determines the maximum frequency you can have in your audio, not quality or detail. One of the remarkable things about digital audio is that if you set the sampling rate 2x higher than you can hear, then going higher had no effect.

Re: What's the correlation between sampling rate and audio frequency (audio pitch)?

Reply #2
Sampling rate determines the maximum frequency you can have in your audio, not quality or detail. One of the remarkable things about digital audio is that if you set the sampling rate 2x higher than you can hear, then going higher had no effect.
Ahh okay. Then what's the point of 24 bit audio with 96kHz sampling rate?


Re: What's the correlation between sampling rate and audio frequency (audio pitch)?

Reply #4
The Audacity website has a simple introduction to how audio is sampled/digized.

Quote
But why exactly does this have effects on the maximum frequency?
The simple explanation is that you need to sample the top half of the wave once per cycle and the bottom half of the wave at least once per cycle.    ...One sample per half-cycle or two samples per cycle, or at least twice the audio/signal frequency.     If the signal is higher than half the sample rate you get aliasing (false frequencies) when the analog signal is re-constructed.

For a more precise & detailed explanation - Nyquist Theory


Re: What's the correlation between sampling rate and audio frequency (audio pitch)?

Reply #5
Ahh okay. Then what's the point of 24 bit audio with 96kHz sampling rate?

Short answer: Marketing.

Slightly longer answer: It makes good sense to use an "overkill" format for recording and processing even if it is not necessary for the end-user product. And since the formats exist for a good reason, someone has found out they can market signals you cannot hear as "HD". (It is a bit like having infrared-capable TV.)

 
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