Joshua Lee is a news and science reporter. He has been one of the leading cannabis reporters in New Mexico for the last five years, and his work has appeared in Weekly Alibi, Right Where You Are Sitting Now and the Disinformation Company.

A new study suggests that smoking cannabis can have lasting changes on users’ voices, but its limitations have made some question its veracity.

According to a new study published in the Journal of Voice, anecdotal evidence supports the theory that cannabis can negatively impact the voices of professional singers and speakers. The study suggests that marijuana use can lead to hoarseness and vocal weakness.

Researchers reportedly surveyed 42 adult patients from study author Robert T. Sataloff’s clinical voice center in Pennsylvania. The majority of participants—about 77 percent—reported having tried some form of cannabis during their lifetime. Around 42 percent of those cannabis users believed that smoking marijuana resulted in immediate changes to their voice. About 29 percent said they believed it had long-term effects on their voices. Those who reported using cannabis on a monthly basis believed that the behavior had led to long-term hoarseness.

“Smoking marijuana can cause voice dysfunction. For high-level voice users such as opera singers, intoxication or alteration in cognitive function from any cause can alter fine motor control and result in voice injury. This is true of marijuana, as it is of alcohol,” Sataloff told reporters.

But some are criticizing the study, pointing out that it relies purely on anecdotal patient reports from a very small focus group—only 42 patients—and fails to produce any amount of clinical evidence.