The Americans with Disabilities Act provides for accommodations for workers and students (504 plan).
The US Department of Labor website says, “Under the Americans with Disabilities Act (ADA), an accommodation is considered any modification or adjustment to a job or work environment that enables a qualified person with a disability to apply for or perform a job. The term also encompasses alterations to ensure a qualified individual with a disability has rights and privileges in employment equal to those of employees without disabilities. The obligation to provide reasonable accommodations for job applicants or employees with disabilities is one of the key non-discrimination requirements in the ADA’s employment provisions.”
The ADA does not identify specific disabilities. Rather it defines a disability as a condition that “substantially limits one or more major life activity.” Misophonia definitely meets this criteria.
The ADA does not grant you the right to have your own office, but it does require your employer to provide reasonable workplace accommodations. For example, simply being able to wear headphones in the workplace, or have a telephone that allows you to use noise cancelling headphones, can make a great difference. You might ask yourself, “Can a deaf person do this job?” If the answer is yes, then you should be able to wear headphones all the time (even if your company has a policy that headphones are not allowed). You will need to help figure out what accommodations will help you.
Talk to your supervisor or human resources department regarding the documentation that your company requires for you to receive accommodations under the ADA. Generally you simply need a diagnosis from someone acceptable to your employer.