This study is for people with chronic cough that doesn't go away with usual treatments. Chronic cough is a cough that lasts a long time, even when other treatments are tried. The study is testing a therapy called behavioral cough suppression (BCS) which helps people learn ways to stop coughing. Another treatment involves inhaling a substance that might make the body less sensitive to things that make you cough. Participants will be split into three groups: two groups will receive BCS with either an active or inactive inhaled treatment, and one group will not receive any treatment but can try BCS at the end.

• Participants must attend 14 clinic visits and 2 online visits.
• Participants will be paid for their time.
• The study checks how well people learn to control coughing and how it affects their lives.

This study will help researchers understand which treatments work best for reducing cough sensitivity and improving life quality. Eligible participants must be between 18 and 99 years old, have a diagnosis of refractory chronic cough, and meet other specific health criteria.