There are 695 pages in this book; unfortunately, I found more than 300 of them to be not what I expected. In the preface, author Professor Raymond Hickey states that:
“… any questions about language [beyond Earth] can only be sensibly addressed after one has ascertained if life on planets elsewhere might be possible, what this life might be like and at what degree of development.”
Parts 1-4 of the book concentrate almost entirely on answering these questions. There are brief comments on the likely physical structure of “exobeings” that have language, such as brain and sensory complexity. However, the rest refers to human evolutionary biology, paleoanthropology and neuroscience, as well as astronomy. The overall message might be summarised as the Drake Equation plus Darwin.

Most of these topics have been extensively (and well) covered elsewhere in recent popular science books. Discussion of non-Earth language — the more original content of the book — only really begins in Parts 5 and 6. Raymond Hickey's speciality is linguistics, and he gives a detailed account of it, interspersed with sections on how this would apply to “exolanguages.” Some attention is paid to communication on Earth by means other than human speech or signing, such as birdsong (but not all other methods — rapidly changing colour patterns and/or luminosity, for example). I would have liked more on the effects that such varying modalities might have on language structure in creatures with advanced cognitive ability. Nevertheless, Parts 5-6 are interesting and gave me new and valuable information. The bibliography is also very useful.

"'Life and Language Beyond Earth” is really two books. For me, the first of these (Parts 1-4) was redundant; I was not looking for a description of evolution or the search for exoplanets etc. The author says that:
“The working title for this book, which as a linguist I had for a number of years, was ‘Language beyond Earth’.”
I believe he should have stuck with the original plan and produced a book focused on that topic, at about half the size.