Compression for Clinicians
RATING: 4 ears (students);
3 stars (practitioners)
EDITOR: Theodore H. Venema
PUBLISHER: Thomson Delmar Learning
ISBN: 978-1-4180-0959-5 (softcover)
REVIEWER: Therese C. Walden, AuD, Chief, Audiology Clinic, Army Audiology and Speech Center, Walter Reed Army Medical Center, Washington, D.C.
SYNOPSIS: This second edition textbook, Compression for Clinicians, provides an excellent and comprehensive explanation of the concepts of compression. The author spends time explaining the anatomy and physiology of the peripheral hearing mechanism and its response to acoustic stimuli so that the reader has a better understanding of the need for compression circuitry in hearing aids. He then outlines the mechanism of compression and the development of practical use in hearing aid technology as we know it today. The summary section found at the end of each chapter is helpful in pulling together the main points. In addition, the review questions section found at the end of each chapter helps the reader solidify the information immediately. Especially helpful are the recommended readings in the reference section.
CRITIQUE: Chapter 1 acquaints the reader with the anatomy and physiology of the cochlea and how it processes acoustic signals. The author goes on to explain the concept of cochlear dead regions in chapter 2. He spends most of this chapter describing the TEN test by Brian Moore, which, although availability commercially and with recent updates to make it more clinician-friendly, has not been embraced by many clinicians for use in the diagnostic test battery. The author does not spend any time discussing research on the concept of dead regions by other contributors and in the summary for the chapter the clinical utility of the TEN is downplayed. Chapter 3 provides an explanation of the speech in noise problem experienced by patients with hearing loss and the author supplies a comprehensive history of the development of prescriptive methods for hearing aid selections. He goes on in Chapter 4 to describe the popular and widely used DSLi/o and NAL-NL1 prescriptive methods as they apply non-linear processing. Chapter 5 contains the essence of the text. The block diagrams will help the reader to understand more fully the similarities and differences among input and output compression as well as wide dynamic range compression concepts. Chapters 6 and 7 outline programmable and digital hearing aids and their capabilities for use in the treatment of hearing loss for the patient. Chapter 8 wraps up the text with an overview of directional microphone technology and its use with and without digital noise reduction algorithms. A point of clarification: The author refers to the former Surgeon General of the United States, C. Everett Koop, M.D. as the Surgeon General (SG) of the Food and Drug Administration when in fact, the Office of the Surgeon General falls under the U.S. Department of Health and Human Services. The FDA is a separate function under the Department of Health and Human Services and although the two services function collaboratively, they have separate top officials. Additionally, Dr. Koop, during his tenure as SG and after, was and continues to be a strong advocate for hearing aid use. He has participated in many venues to emphasize the importance of early and effective treatment of hearing loss.
This textbook was a pleasure to review and can become a valuable and useful addition to any audiologist’s reference library.