The book "The auditory system as the most direct, straight-line method for the simultaneous four-fold mastery of a foreign language" by Charles Hardy is a study of a unique approach to learning foreign languages, which offers an effective method based on auditory processes. The author proves that auditory perception can become a key component in language acquisition, helping to simultaneously develop four skills - reading, writing, speaking and understanding. This book will be a valuable resource for anyone who wants to improve their language learning skills, as well as for teachers looking for new teaching methods.