Frequency Analysis of Audio Signals

Frequency Analysis of Audio Signals

Frequency Analysis of audio signals is taking the audio signals that are desired to be examined and placing them in the frequency domain to observe how the signals respond to all the various frequencies of a given bandwidth.

Usually when a signal is recorded regularly, it is in the time domain. In order to convert it to the frequency domain, a special audio software must be used that can perform frequency analysis. The user can then specify which bandwith, or range of frequencies, he wants to examine the audio signal in.

Below is an audio signal recorded in the time domain:

Microphone Signal

Here, when an audio signal is in the time domain, you can see only the amplitude of the signal and nothing else. This amplitude is the RMS amplitude, or in more understandable terms, the average amplitude of the signal averaged at all the various frequencies for the bandwidth in mention.

Now below is the audio signal in the frequency domain:

Frequency Analysis Graph

Here you can see what amplitude the audio signal produces at each specific frequency. While the time domain amplitude only gives you the RMS amplitude averaged at all the various frequencies, examining the audio signal in the frequency domain allows you to see each and every individual amplitude for each frequency.

Frequency analysis is important because it is crucial to know how audio devices amplify sound at certain frequencies. Speakers and microphones need to amplify certain sounds depending on the application at use. For example, a speaker may need to play out high-frequency sounds, so it must be able to amplify sound well at high frequencies.Thus, it is important to perform frequency analysis on the speaker to make sure this is the case. To see a more in-depth discussion on the importance of frequency analysis, see Why is it Important to Perform Frequency Analysis on Audio Signals.

Related Resources

Frequency Analysis of the Noise Cancellation Ability of a Microphone

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