Sravaka (Sanskritśrāvaka; Tibetannyan thos; Palisāvaka) is a hearer, a term applied to the personal disciples of the Buddha, distinguished as mahā-śrāvaka; it is also applied to hearers, or disciples in general; but its general connotation relates it to Hīnayāna disciples who understand the four dogmas, rid themselves of the unreality of the phenomenal, and enter nirvāṇa; it is the initial stage.
External links
Digital Dictionary of Buddhism (http://www.acmuller.net/cgi-bin/search-ddb4.pl?Terms=聲聞) (log in with userID "guest")
The Mahayana unequivocally says that a Buddha, a Pratyekabuddha and a Sravaka (disciple), all three are equal and alike with regard to their purification or liberation from defilements or impurities (Klesavaranavisuddhi).
sravaka, disciple) liberated through wisdom are equal with regard to their Vimutta (liberation), but the Tathagatha is different and distinguished from the liberated bhikkhus in that he (Tathagata) discovers and shows the Path (Magga) that was not known before.
Bent on his or her liberation, a Sravaka follows and practises the reaching of the Buddha and finally attains Nirvana.
It is not conceivable that Sravakas and Bodhisattvas are concentrated in separate geographical areas.
These three states of the Sravaka, the Pratyekabuddha and the Buddha are mentioned in the Nidhikanda Sutta of the Khuddakapatha, the first book of the Khuddaka-nikaya, one of the five Collections of the Theravada Tripitaka.