NOTE: To all, the speech is by Swami Vivekananda but the voice is not his, it was recorded later to convey the message to masses, the audio recording was done by “Subir Ghosh”.
Regarding the original voice of Swamiji, there is an interesting article by M S NANJUNDIAH published in the ‘Vedanta Kesari’ August 2010 issue.
Please go through the above article in the following link:-
Before concluding we need to mention that, at present, the only audio recording available of the direct disciples of Sri Ramakrishna is that of Swami Abhedananda which was aired on All India Radio.
So, Please Try to concentrate on the message rather than the medium!