श्रवणं तस्य देवस्य श्रोतव्याभावचिन्तनम् ।मननं त्वात्मलिङ्गस्य मन्तव्याभावचिन्तनम् ॥ २९ ॥
In plain words
'Hearing' the Deity means realizing there is nothing further left to hear. 'Reflecting' on the Self within, in turn, means realizing there is nothing further left to reflect on.
Close to the Sanskrit
The hearing of that Deity is the contemplation of the absence of anything left to hear; the reflection on the Self-liṅga, however, is the contemplation of the absence of anything left to reflect upon.