This is an excerpt from wikipedia about 'full rate' speech coding standard.
Full Rate or FR or GSM-FR or GSM 06.10 was the first digital speech coding standard used in the GSM digital mobile phone system. The bit rate of the codec is 13 kbit/s, or 1.625 bits/audio sample.
And this one is an excerpt from Wikipedia about bit.
In computing parlance, bit is the abbreviation for a single binary digit, represented by a 0 or a 1.
How could I represent 1.625 by 0 or a 1?
Actually, that's my lecturer's question that I could not answer. Some links to papers are more than welcome.
Thanks in advance.