Linearization of photoacoustic spectra is a technique that allows for detection of surface layers and the compensation of saturation effects in photoacoustic spectra by combining amplitude and phase information. The objective of this report is a thorough description of the linearization procedure. The influence of interferogram rotation on the real and imaginary parts of the complex Fourier transformation and on spectral phase angles is shown. The possibility of using the linearization approach to correct for phase differences between reference and sample data is discussed. The method can be used to calculate phase spectra from photoacoustic spectra taken with rapid scan spectrometers.