Apparatus and Method for Generating a High Requency Audio Signal Using Adaptive Oversampling

An apparatus for generating a high frequency audio signal that comprises an analyzer (12) for analyzing an input signal to determine a transient information adaptively. Additionally a spectral converter (14) is provided for converting the input signal into an input spectral representation. A spectral processor (13) processes the input spectral representation to generate a processed spectral representation comprising values for higher frequencies than the input spectral representation. A time converter (17) is configured for converting the processed spectral representation to a time representation, wherein the spectral converter or the time converter are controllable to perform a frequency domain oversampling for the first portion of the input signal having the transient information associated and to not perform the frequency domain oversampling for the second portion of the input signal not having the associated transient information.