Slips of the ear are of great relevance in the study of how listeners process speech. Our interest in speech misperceptions comes from their value as diagnostic stimuli in evaluating computational models of speech perception in noise. Previous corpora of misperceptions have largely been recorded based on reports of isolated occurrences ‘in the wild’, and consequently are not available for further analysis or replication. The current study involves the elicitation in the laboratory of a corpus of over one thousand robust misperceptions of Spanish words induced by stationary and non-stationary maskers. Misperceptions are analysed into single-phoneme substitutions, insertions and deletions, dual vowel/consonant changes, syllable insertions/deletions, compound reformulations and eccentric cases which defy simple explanation. A novel categorisation scheme based on the interaction between the background and foreground is introduced. The new corpus will permit the evaluation of speech perception models that make detailed predictions of listeners’ responses to specific speech-in-noise tokens.