# AudioFrequencyShift

AudioFrequencyShift[audio,freq]

gives audio by shifting the spectrum of audio by freq.

AudioFrequencyShift[audio,freq,mix]

uses mix to control the ratio between the original and shifted audio.

AudioFrequencyShift[video,]

shifts the spectrum of the first audio track in video.

# Details and Options

• AudioFrequencyShift shifts every frequency f in the input signal to frequency .
• The frequency freq can be a scalar or a frequency quantity, an Audio object, a pure function, or a TimeSeries.
• The mixing parameter mix can be any real number between 0 and 1. The default value is 1.
• With mix=0, only the original signal is returned; with mix=1, only the delayed signal is returned.
• AudioFrequencyShift accepts a Method option. Possible settings are:
•  "UpperSideband" the spectrum is shifted by freq "LowerSideband" the spectrum is reversed and shifted by freq "AmplitudeModulation" both effects are present at the same time
• The absolute amount of shift should be less than half of the Nyquist frequency.

# Examples

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## Basic Examples(2)

Shift the spectrum of an audio signal by 1000 Hz:

Plot the power spectrum of the original and shifted signals:

Mix the original signal with the shifted one:

## Scope(6)

Control the ratio between the original and the frequency-shifted signal:

The shift given as a number is assumed to be in hertz:

Use a frequency quantity:

Time-varying frequency shift using a function:

Time-varying frequency shift using a TimeSeries:

Time-varying frequency shift using a control audio signal:

Process the audio track of a video:

## Options(2)

### Method(2)

AudioFrequencyShift can use three methods:

While "UpperSideband" and "LowerSideband" produce very similar results, "AmplitudeModulation" generates a different sound:

## Applications(2)

Create a chorus effect using a small amount of shift while mixing in the original signal:

Use frequency shifting to produce complex inharmonic sounds:

Use frequency shifting to "tune" drum-like sounds:

Use frequency shifting to "mask" voices:

## Properties & Relations(1)

Shifting harmonically simple signals like sinusoids changes the perceived pitch:

Shifting complex signals alters the harmonic relationships between their components and can produce an inharmonic output:

## Possible Issues(1)

The absolute value of the shift parameter needs to be less than one-quarter of the sample rate:

Increase the sampling frequency of the input to overcome this limitation:

## Neat Examples(2)

Simulate the behavior of an AM radio:

Shift the original signal to a higher frequency:

Reconstruct the original audio:

Time-varying frequency shift using a RandomWalkProcess:

Wolfram Research (2016), AudioFrequencyShift, Wolfram Language function, https://reference.wolfram.com/language/ref/AudioFrequencyShift.html (updated 2024).

#### Text

Wolfram Research (2016), AudioFrequencyShift, Wolfram Language function, https://reference.wolfram.com/language/ref/AudioFrequencyShift.html (updated 2024).

#### CMS

Wolfram Language. 2016. "AudioFrequencyShift." Wolfram Language & System Documentation Center. Wolfram Research. Last Modified 2024. https://reference.wolfram.com/language/ref/AudioFrequencyShift.html.

#### APA

Wolfram Language. (2016). AudioFrequencyShift. Wolfram Language & System Documentation Center. Retrieved from https://reference.wolfram.com/language/ref/AudioFrequencyShift.html

#### BibTeX

@misc{reference.wolfram_2024_audiofrequencyshift, author="Wolfram Research", title="{AudioFrequencyShift}", year="2024", howpublished="\url{https://reference.wolfram.com/language/ref/AudioFrequencyShift.html}", note=[Accessed: 09-September-2024 ]}

#### BibLaTeX

@online{reference.wolfram_2024_audiofrequencyshift, organization={Wolfram Research}, title={AudioFrequencyShift}, year={2024}, url={https://reference.wolfram.com/language/ref/AudioFrequencyShift.html}, note=[Accessed: 09-September-2024 ]}