# Frequency detection in audio and what parameter or set of parameters help/limit frequency detection

I'm trying to learn audio and voice/speech processing techniques out of interest. I intend to learn, experiment with algorithms and design, implementation of such systems, frameworks using programming languages like C/C++, Python, Matlab. Right now, to begin with, I'm only interested in audio or speech detection and not in speech recognition. I did some basic reading and research into this. Would like to understand a few basic concepts:

1. How to detect the presence of human speech (voice frequency of male being between 85 Hz to 180 Hz, and that of female voice frequency between 165 Hz to 255 Hz but maximum range being 20 Hz to 20 kHz), differentiate them from other frequencies, identify noise etc?

2. Being aware of the sampling theorem and the limitations of using lower sampling rates, how to know if any error was introduced during digital transmission or during reconstruction of the signal in analog domain from the digital domain (i.e., error detection) ?

3. How to detect tones (produced digitally or externally recorded analog tones) and music notes? Do they follow similar techniques as speech? If no, how are they different?

I seek guidance, if not direct answers, on how to proceed with the learning the concepts and reading material. Any help in this regard will be grateful.

• Your question is not in a format likely to attract answers. In general, it is preferred if you ask only one question, and if that question is very specific. Also, many of the subjects you want to learn on have multiple answers on this site, so it may be worth it to spend some time using the search engine.
– MBaz
Sep 27, 2018 at 15:16
• You might also want to research how pitch detection is different from frequency detection. This is a very important difference for speech and music. Sep 27, 2018 at 15:33
• I'm not sure your voice frequency numbers are correct, they look about right, but your units are off by a "k". Sep 27, 2018 at 15:43
• @CedronDawg Oops. Thanks for pointing it out. Fixed it. Sep 28, 2018 at 3:43
• @skrowten_hermit Given that you haven't got any answers yet, I'd suggest trying again, with one specific question per post.
– MBaz
Sep 28, 2018 at 13:46