For more than sixty years, people have claimed to capture mysterious voices on recording media. They have been called Electronic Voice Phenomena, or EVP, and interpretations of their origin range from the voices of the dead to fragments of ordinary speech, radio interference, psychological suggestion, and simple noise.
But before asking where an unexplained voice came from, there is a more fundamental question:
Was it actually a voice?
The EVP Code: A Phonetic Approach to Electronic Voice Phenomena introduces paranormal investigators and serious researchers to the science of phonetics and acoustic analysis as a new way of approaching that question.
Drawing on thirteen years of investigative experience, author Michael J. Baker moves EVP analysis beyond repeated listening, filtering, and subjective interpretation and asks what evidence of human speech can actually be measured in a recording. Rather than attempting to prove or disprove the paranormal, The EVP Code provides investigators with practical tools for distinguishing genuine speech-like structure from ambiguous sound and for recognizing when the available evidence simply cannot support a conclusion.
Beginning with the fundamentals of human speech production, the book explains how vowels and consonants leave identifiable acoustic signatures and how those signatures can be examined visually using spectrograms. Readers learn how to recognize formants, fricatives, plosives, nasals, approximants, affricates, and other building blocks of speech, and how measurements such as F1 and F2 can help narrow possible vowel sounds.
Step by step, the book introduces the use of Praat and other analytical tools, explains how to read spectrograms, explores the effects of speaker characteristics and vocal-tract anatomy, and demonstrates how a suspected EVP can be examined from raw audio to cautious phonetic interpretation.
But acoustic measurement is only part of the problem.
The EVP Code also examines auditory pareidolia, expectation bias, contextual priming, and the powerful influence suggestion can have on what listeners believe they hear. It explores blind testing, independent analysis, inter-rater agreement, and other methods investigators can use to reduce bias and make their conclusions more reproducible.
For readers ready to go deeper, later chapters introduce advanced acoustic measurements including jitter, shimmer, harmonic-to-noise ratio, and spectral tilt. The book also examines the growing role of machine learning and automatic speech recognition, explaining both their potential and the danger of treating confident computer-generated transcripts as evidence.
Throughout the book, one principle remains constant: the goal is not to force every recording to produce an answer.
Some recordings contain enough acoustic information to support a phonetic interpretation. Others support several possibilities. Some are simply too short, noisy, degraded, or ambiguous to determine what was said, or whether speech was present at all.
Learning to recognize that difference is the heart of The EVP Code.
Written for paranormal investigators without requiring a background in linguistics or acoustics, the book translates technical concepts into practical methods that can be used in real investigations. Charts, diagrams, spectrograms, worked examples, case studies, and reference material allow readers to follow the analysis themselves and return to the book as a field reference.
