Compression for Clinicians (1999). By Theodore H. Venema. Singular Publishing Group, Inc., San Diego & London. $43.95. Reviewed by Derek E. Dunn, Washington, DC.

The author's goal is to present an easy-to-read review and explanation of the concepts underlying signal compression in hearing aids so that clinicians can understand how to apply these concepts to selecting/fitting hearing aids. The intended audience is anyone fitting hearing aids and students. The book chapters cover an anatomic/physiologic description of the cochlea, an overview of hearing aid fitting methods, understanding loudness growth functions, the many ways compression is incorporated in hearing aids, the major classes of hearing aids and their capabilities/limitations, and how compression is a factor in various suprathreshold hearing aid selection methods. Each chapter has a summary of key points and a recommended readings section. There is a section that lists the references cited throughout the book, and the appendices include technical background information and reprints of two relevant publications.

The text provides a good summary and explanation of compression and its use in hearing aids. A person unfamiliar with signal compression but tasked with fitting hearing aids that use compression technology would benefit from the information presented. The references and recommended readings will be very useful for the student or clinician wishing to delve deeper into the area.

The book is written in an easy-to-read, almost conversational, style. This is a benefit in most cases, but there are a few instances in the section on cochlear physiology where the material is a bit oversimplified and might result in misconceptions on the part of an inexperienced reader. The potential misconceptions would not adversely impact clinical decisions, but some statements are contrary to information found in rigorous technical publications.

The author's straight-forward writing style is very helpful in the core chapters dealing with the technical aspects of loudness growth, various compression circuits, and digital/programmable hearing aids. These core chapters will be of interest to clinicians wishing to gain a more thorough understanding of the principals underlying the various hearing aid-fitting methods. The broad range of information is easily digested. Although this book is intended for all health professionals engaged in fitting hearing aids, it will prove more useful to those beginning to fit hearing aids than clinicians who are experienced in providing hearing aid services. Students would benefit most by reading the book prior to receiving training in fitting hearing aids and then referencing the text during training. This text is recommended for students and clinicians providing hearing aid services.