Using novel audio hardware and specialized software this project shall research and develop a system that recognizes patterns of breath sounds within subjects who have sleep apnea hypopnea syndrome (SAHS) or its most serious aspect - Obstructive Sleep Apnea (OSA). Upon completion (two Phases) of the project, the deliverable, called Tooth Phone(R) System for Sleep Apnea Monitoring (TPS-SAM), shall be a system that on a nightly basis, monitors the treatment compliance and efficacy of mandibular advancement devices (MADs) used to treat sleep apnea. To achieve the project deliverable the Phase I has four Specific Aims. They are: (Aim 1) Refine the audio hardware (tooth microphone) previously developed and integrate the tooth microphone into an oral appliance - specifically into a MAD, test for safety of the integrated MAD, and deliver several prototype data acquisition devices that record audio data from the integrated MAD; (Aim 2) Test the prototype devices and integrated MAD on human subjects in a sleep lab for (a) SAHS-event identification with audio, and (b) human factors such as comfort and ease of use; (Aim 3) Using specialized software previously developed, analyze the audio (tooth microphone) data files recorded in the sleep lab and identify events related to SAHS; (Aim 4) Contrast and compare the software results of Aim 3 against control microphone SAHS event identifications taken during sleep lab polysomnography (PSG). Phase I feasibility is achieved if the identification of SAHS events by the TPS-SAM system achieves a 85% accuracy (with 88 % sensitivity and 70 % specificity) when compared to the CONTROL estimation provided by PSG through analysis of standard parameters by sleep doctors. During Phase II the prototype shall be refined and audio data clinically correlated to standard PSG indicators of sleep apnea. If successful, benefits of this Project include: (1) Use of ONE sensor nightly to monitor SAHS, which potentially eliminates the need for subsequent titration PSGs, improves treatment efficacy, and lowers cost, (2) A new stand-alone system for patients at home to titrate oral appliances, (3) A system for researchers to compare the clinical effectiveness of different MAD designs, (4) An aid in long-term population studies of treatment effectiveness by MADs for a specific level of OSA (mild, moderate, severe - as diagnosed by PSG - not by the proposed TPS-SAM), and perhaps most significantly, (5) The introduction of a novel hardware platform and automated computerized method to monitor ALL breath sounds (speech and non-speech), which in an era of Big Data and the NIH - BD2K initiative, can lead to an entirely new way to monitor and diagnose many respiratory illnesses and pathological conditions.