This is the 3923rd most frequent German word.
tiefe
"Depth."
Here, 'tiefe' is used as a noun referring to the depth, which is a measurement of how deep something is.
Die tiefe des Ozeans ist beeindruckend.
The depth of the ocean is impressive.
In this sentence, 'tiefen' is used as an adjective describing the word 'Stimme' (voice), indicating the low frequency of the sound.
Er sprach mit einer tiefen Stimme.
He spoke with a deep voice.
Here, 'Tiefe' refers to the profoundness or intensity of emotions, showing its abstract use regarding intensity.