Try disabling using OpenAL or replacing Creative’s OpenAL32.dll included with ioq3 1.36 installer with OpenAL Soft. To disable using OpenAL open the console using ~ or shift+escape and type s_useOpenAL 0; snd_restart and press enter. If it doesn’t help you can switch back using s_useOpenAL 1; snd_restart.
Try switching from the modern-ish GPU intensive OpenGL2 renderer to the classic OpenGL1 renderer. Open the console using ~ or shift+escape and type cl_renderer opengl1; vid_restart and press enter. You can switch back using cl_renderer opengl2; vid_restart.