Despite the success and widespread use of Automatic Teller Machines (ATMs), a significant proportion of bank customers can not or will not use them, or experience difficulties in their interactions. Speech technology has been suggested as a means by which non-users might be encouraged to use ATMs, while simultaneously improving usability for all. The potential advantages of speech interfaces include hands-free and eyes-free use for physically- and visually-impaired users, and improved ease and speed of use through increased 'naturalness' of the interaction. This study investigated user attitudes to the concepts of a speech-based ATM, via large-scale survey and a series of focus groups. Objective performance was also considered in user trials with a prototype speech-driven ATM. The idea of using speech for ATM transactions led to a number of concerns. Privacy (the concern over one's personal financial details being overheard) and security (the fear of potential attackers hearing the user withdraw cash) were the major reasons given. The user trials confirmed that possible solutions, such as the adoption of a hood over the ATM or the use of a telephone handset as the speech input/output device, were ineffective. Groups of impaired users, particularly visually-impaired subjects, were more positive about the concept of speech, citing various difficulties with current visual-manual interactions. Most non-users, however, would not be encouraged to use ATMs with the addition of speech. The paper discusses these and other issues relating to the likely success of using speech for ATM applications.