You’ve been asked to convert a Windows WAV file into an MP3 file with a setting of 44.1kHz. What does the kHz option mean?
A) The maximum number of kilobits per second of audio
B) The number of sample points per second
C) The number of bits of information recorded for each audio sample
D) The duration of the converted file, in seconds
Answer: B) The number of sample points per second
To create a digital file from audio, the analog sounds that we humans hear are converted to many tiny audio samples, usually thousands of these samples every second. A hertz is a measure of frequency per unit of time, therefore the kilohertz of an audio file are a reference to thousands of audio samples per second. The setting of 44.1kHz is 44,100 samples of audio per second.
The incorrect answers:
A) The maximum number of kilobits per second of audio
The audio bit rate in kilobits per second of audio is calculated by multiplying the bit depth (in bits), the sampling rate (in kHz), and the number of channels. If you change any of these variables, the kilobits per second will change accordingly.
C) The number of bits of information recorded for each audio sample
The number of bits of information recorded for each audio sample is called the audio bit depth, and it’s usually described as a number of bits (i.e., 8-bit, 16-bit, 24-bit).
D) The duration of the converted file, in seconds
The duration of the file should be exactly the same in any format, unless you’ve done something horribly wrong!
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Want to know more? Watch “Installing, Configuring, and Upgrading Audio.”The use of audio in personal computers has evolved dramatically through the years, and the current assortment of audio hardware devices and software is varied enough to keep even the most knowledgeable technicians guessing. In this video, we’ll show you common audio input and output methods, discuss the details of sample rates, examine the differences between audio bit depths, and perform some audio configurations in Windows XP. |