Instruct: Classify the given review into positive or negative sentiment.
Query: The book sheds light on tinnitus and other hearing problems.

The book was originally written in the late 1980's according to the copy I recently read. I feel further research information must be available since then. I don't know if this verson is updated. The book is written to an English audience and makes many references to the British health care system.I do recommend this book, even if it is in its original form. The many letters from sufferers and their solutions may be of great help to some.