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What kind of speech is sampled at 8 kHz?
The speech signal sampled at 8 kHz is termed as narrowband speech and the speech signal sampled at 16 kHz is termed as wideband speech. For practical speech signal processing, if the speech signal is available from a telephone or mobile channel, we have left with little option, but to process the speech signal at 8 kHz sampling frequency.
What is the relationship between sample rate and frame rate?
If yes, what is mathematical relationship between them for given values of window length (L), window shift (R), Sampling frequency (Fs) and Frame Rate (FR)? The sample rate divided by the frame rate will give you the window shift in samples.
Why is 8 kHz chosen as the sampling frequency?
Hence 8 kHz was chosen as the sampling frequency for the telephone communication. By listening to the three files, namely, file sampled at 44.1 kHz, file sampled at 16 kHz and file sampled at 8 kHz, one can observe difference in the naturalness between the speech sampled at 8 kHz and other higher sampling frequencies.
What is the frequency range of a speech signal?
The speech signal has frequency components in the audio frequency range (20 Hz to 20 kHz) of the electromagnetic spectrum. This is the reason for perceiving the information present in the speech signal by human ears.
What’s the minimum sample rate for a sound wave?
According to Nyquist’s Theorem, for an accurate digital representation of a sound wave, the sample rate must be, at least, two times bigger than the highest frequency going to be recorded. As the highest sound a human can hear has a frequency of 20 kHz, the minimum sample rate must be 40 kHz to be possible to digitalize this frequency.
Which is the minimum sample rate for digitalization?
As the highest sound a human can hear has a frequency of 20 kHz, the minimum sample rate must be 40 kHz to be possible to digitalize this frequency. With that, if no human can hear anything higher than 20 kHz, why bother having a sample rate above 40 kHz? Actually, why is the minimum standard 44.1 kHz instead of 40 kHz?
What is the sampling frequency and bit resolution for mobile communication?
For mobile communication, even though the sampling frequency remains same at 8 kHz, the bit resolution varies over a wide range starting from 8 bits/sample to 0.25 bits/sample and accordingly we have wide bit rate ranging from 64 kbps to as low as 2 kbps.