Some audio workstations for editing and mixing audio support the .sd2f audio files (Sound Designer 2) and can import and work with it and perhaps also export it as a common .wav file. One of such known apps is Logic Pro for OS X, but perhaps more could be found.
Convert Sound Designer 2 audio to WAVe PCM Sound, standard Windows sound format.
We have found one software suitable in our database for this conversion.
Apple macOS / Mac OS X software - convert sd2f to wav on OS X
A digital audio workstation and MIDI sequencer program
Convert from sd2f file format
The table with program actions contains information about what each program is capable of doing with their files. This may be a good pointer for further searches for certain file conversions and help you find the converter you are looking for if our search result is insufficient for you. However, it is far from perfect and may sometimes show results which are not really usable because of the nature of the software handles the files. So a conversion that appears as possible, just because of matched actions, may in fact not be possible.