Odiorne (1954) was, to our knowledge, the first to conduct a study that expressly focused on the communication needs and experiences of employees. However, the real history of communication audits started 25 years later, following the publication of the ICA (International Communication Association) Communication Audit by Goldhaber and Rogers (1979). The audit was developed by more than 100 communication professionals-academics as well practitioners-from the ICA Organizational Communication division. The resulting book contained a detailed description of the communication audit process, from planning to interpreting and reporting, and a first listing of communication audit methods.The publication of the ICA Communication Audit led to a first wave of books about communication audits in the 1980s. Booth (1986), Hamilton (1987), and Downs (1988 all published comprehensive books about communication audits. The contents of those books were in line with Goldhaber and Rogers (1979), in that they paid attention to both the audit process and specific research instruments. Goldhaber (1993) included a chapter on communication audits in his book on organizational communication. After a period of silence, the second wave of publications on communication audits started with a handbook by . This was followed by contributions by Downs and Adrian (2004) and a revised and updated edition of Hargie & Tourish's book (2009).Hargie and Tourish (2000) define communication audits as "the assessment of current [communication] practice (diagnosis) in order to determine what steps are required to secure improvement (prescription)" (p. xv). The combination of the three elements (1) assessment/ evaluation, (2) diagnosis, and (3) prescription/ improvement can be found in all views on communication audits. As such, communication audits are a form of applied communication research at the crossroads of research methodology and organizational communication theories.In the early days of the communication audits, it was suggested that a full communication audit would require the combination of many different data 13 collection methods. This manifested itself in metaphors used to describe the auditing process. Goldhaber and Rogers (1979), for instance, compare a communication audit to a financial assessment and an annual health check-up. Throughout the years, this characteristic diminished in importance. Instead of a comprehensive, costly, and time-consuming approach to evaluate all aspects of an organization's communication system, the communication audit is increasingly seen as a toolbox with techniques that can be purposefully used to optimize an organization's communication.Despite the attention for the phenomenon of communication audits in the two waves, the methodological research into the merits and restrictions of the various audit techniques has been very limited. Most articles reporting on research into communication audits present case studies with overall results of combinations of methods in specific organizations (e.g.,