Mourinho: 'Arsenal's defending to get rougher'

• Become laryngitic
• Make raspy
• Become harsh, as a voice
• Get rough, as a voice
• Become raspy, as one's voice
• Make rougher, as a voice

The Collaborative International Dictionary Word definitions in The Collaborative International Dictionary
Hoarsen \Hoars"en\, v. t. [imp. & p. p. Hoarsened ; p. pr. & vb. n. Hoarsening .] To make hoarse. I shall be obliged to hoarsen my voice. --Richardson.

Wiktionary Word definitions in Wiktionary
vb. (context transitive intransitive English) To make or become hoarse.