Possible Clues:

• Spoke with speech defect of sibilants
• Didn't speak clearly
• Used "th" in place of "s"
• Talked like Sylvester
• Spoke with sibilant defects
• Used interdentals improperly
• Had trouble pronouncing ''s''
• Used ''th'' in place of ''s''
• Had a speech problem
• Talked like thith