This paper presents preliminary acoustic-phonetic decoding results for Spanish on the spontaneous speech corpus C-ORAL-ROM. These results are compared with results on the read speech corpus ALBAYZIN. We also compare the decoding results obtained with the different types of spontaneous speech in C-ORAL-ROM. As the most important conclusions, the experiments show that the type of spontaneous speech has a deep impact on spontaneous speech recognition results. Best speech recognition results are those obtained on speech captured from the media.