Terminated: Study halted prematurely and will not resume; participants are no longer being examined or receiving intervention.

To investigate if signal processing can detect subtle changes in speech production clinically relevant to oropharynx anatomy that may provide an objective measure in the assessment of the presumed difficulty of intubation.

The purpose of this study is to investigate whether changes in phonation (sounds coming from vocal cords that occur when a person speaks) can be used as a reliable measure to predict airways that may be difficult to manage in the operating room.

One of the reasons the Preoperative Surgical Assessment (PSE) is performed is to assess subjects for signs of a difficult airway. At this time, none of the assessments have proven to be both highly sensitive and specific. Multiple studies have shown that specific characteristics of a subject's speech can suggest that they may have an issue with the anatomy of the oropharynx (the area consisting of the back of the throat to the vocal cords). Prior research has shown that studying velar vowel sounds, those vowels that require the use of the back of the tongue to pronounce, can be used to predict a disorder called obstructive sleep apnea (a disease associated with difficulty breathing).

The Investigators are trying to determine whether the development of a simple voice study conducted during the PSE visit could alert the Anesthesiologist caring for the subject in the operating room to use the extra precautions provided for people who have a documented history of a difficult airway. It is hoped that the voice analysis test being developed in this study will have the ability to objectively predict a difficult airway for future patients.

Inclusion Criteria:

• 18 years of age or older
• Able to provide informed consent
• A known documented history of having a difficult airway
• An age-matched control subject with normal airways.

Exclusion Criteria:

• Unable to consent for themselves
• Non-English speaking subjects
• Pregnant Subjects
• Previous Vocal Cord Surgery
• Previous Head and neck surgery that would alter anatomy of hypopharynx

We will not include:

• Prisoners
• Pregnant women
• Individuals who are not yet adults (infants, children, teenagers)
• Adults unable to consent
• Adults who cannot speak English We will not be enrolling subjects who cannot speak English. The subjects must be able to understand the research team member who is testing them as well as the research paradigm.

Subjects with a documented history of difficult airways and subjects of the same age (matched for age) with normal airways to be used as controls. Patient are labeled as a difficult airway during their hospitalization, they are given a copy of the difficult airway documentation so the patient should be aware already that they are labeled as a difficult airway.

Terminated: Study halted prematurely and will not resume; participants are no longer being examined or receiving intervention

Adverse events were collected during study participation of 1 day.

Below minimal risk study and participation of 1 day resulted in no adverse events.

Due to technical issues, audio recording could not be uploaded or analyzed as anticipated/planned for study, and enrollment did not meet expectations. Therefore, no analysis or results for the study are available.