"The efforts were intensified"
"Her rudeness intensified his dislike for her"
"Pot smokers claim it heightens their awareness"
"This event only deepened my convictions"

"The debate intensified"
"His dislike for raw fish only deepened in Japan"

"They deepened the lake so that bigger pleasure boats could use it"

"His voice began to change when he was 12 years old"
"Her voice deepened when she whispered the password"