I have been shown how to filter a noisy audio track using Audacity. Audacity forum link here
Audacity accepts python script commands however not for the crucial noise reduction function. I have looked for a command line tool to do this process and SoX appears to be suitable.
The 1st step in Audacity is to apply the following: Effect > Filter Curve > Manage > Factory Presets > Telephone Filter
Reading the SoX manual - SoX does not provide a filter curve. SoX does however provide this.
equalizer frequency[k] width[q|o|h|k] gain
Apply a two-pole peaking equalisation (EQ) filter. With this filter, the signal-level at and around a
selected frequency can be increased or decreased, whilst (unlike band-pass and band-reject filters)
that at all other frequencies is unchanged.
frequency gives the filter’s central frequency in Hz, width, the band-width, and gain the required
gain or attenuation in dB. Beware of Clipping when using a positive gain.
In order to produce complex equalisation curves, this effect can be given several times, each with a
different central frequency.
Is this the right SoX function to use? How do I use this function to achieve the EQ curve?
Regards,
Derek Noffke
PurpleSwift
Cell: 082 780 4680
Tel: 021 761 8264