Telephone

Telephone is the effect template where it often filter out high and low frequencies that are outside normal human voice ranges to save on data transfer costs, and that's what gives telephones (at least, old ones) their distinctive sound.

In Audacity, apply the low-pass filter into 2000.0 hertz. Apply the high-pass filter into 500.0 hertz with the harsh roll-off. Apply the compressor by setting the threshold into -30 decibels.

In Kdenlive, you gonna also apply the 3-level threshold, Colourise it by setting the hue 110, saturation 180, and the lightness 280. Apply the lumakey but don't change these values because this is default. Now by the way, apply the pixelise by the setting the block width into 17 and the height which is the 30 value to make it look distinctive.

Tip: If you want to text, symbol, or a source made to be coloured black like in a text on a telephone screen, make sure to put the invert at the top below the 3-level threshold.