Sounds themselves are analog signals. We have the liberty to choose to record these sounds by either analog or digital means.
Analog recordings capture the continuous wave of the analog signal and what they hear is what they record. Which is why analog tape recording machines are known for their accuracy in capturing signals.
Digital recordings operate a little differently…
They pretty much capture binary codes that reflect the sound’s intensity and pitch at precise intervals.
Simply put, digital recordings sample the analog signals of a sound and then reconstruct these samples upon playback.
A recent question I got was from someone basically asking whether we hear in analogue and I thought this would be a great idea for an article.
With that said, Do we hear in analogue?
Human beings hear in analogue which is a physical representation of sound. This is why computers utilize sound cards that are able to convert digital signals into analogue signals for us to perceive the physical sound itself.
Hearing
In simple terms, hearing is simply the process by which the ear transforms sound vibrations in the environment into impulses that are conveyed to the brain, so they can be interpreted as the sound we perceive.
This process happens so seamlessly.
Sounds are produced when vibrating objects produce pressure pulses of vibrating air molecules (sound waves).
The ear is able to distinguish different aspects of a sound, such as its loudness and pitch.
It does this by detecting and analyzing different physical characteristics of the waves.
What we call pitch is simply the perception of the frequency of a sound wave. Frequency is usually measured in hertz.
The human ear is most sensitive to frequencies of 1,000 to around 4,000 hertz. It can easily detect this frequency range.
However, for normal and young ears the audible range of sounds extends from about 20 to 20,000 hertz.
Loudness
Loudness is how we perceive the intensity of sound.
This means that, the greater the pressure or intensity, the greater the loudness of the sound.
The intensity of sound is measured in decibels abbreviated as dB which is defined as a unit that expresses the relative magnitude or size of a sound on a logarithmic scale.
Stated simply, a decibel is a unit used for comparing the intensity of sound with a standard sound that is just perceptible to the normal human ear at a frequency in the range to which the ear is most sensitive.
On the decibel scale, the range of human hearing extends from 0 dB, which represents a level that is all but inaudible, to about 130 dB, the level at which sound becomes painful.
Digital Signals
Digital audio is a representation of sound that is recorded.
This sound is converted to digital form.
In digital audio, the sound wave of the audio signal is encoded in numerical form in a continuous sequence.
Digital audio is also the name given to the entire technology of sound recording and reproduction using audio signals that have been encoded in digital form.
In a digital audio system, an analog electrical signal representing the sound is converted with an analog-to-digital converter (like a sound card or an audio interface) into a digital signal, typically using pulse-code modulation (PCM).
This digital signal can then be easily recorded, edited, modified, and copied using computers, audio playback machines, and other digital tools.
When the sound engineer wishes to listen to the recording on headphones or loudspeakers or when a consumer wishes to listen to a digital sound file like a song,
A digital-to-analog converter performs the reverse process,
which is converting the digital signal into an analog signal, which is then sent through a speaker and can be perceived by our ears.
Analog Signals
Analog signals are continuous signals in which one time-varying quantity represents another time-based variable.
These kind of signals works with physical values and natural phenomena such as earthquake, frequency, etc.
Before we go a lot further, let’s get a working definition of what a signal actually is, electronic signals to be more specific.
The signals I’m referring to are time-varying “quantities” which convey some sort of information or data.
In electrical engineering the quantity that’s time-varying is usually voltage if its not that, it’s usually current.
So you can think of signals as a voltage that’s changing over time.
Signals are passed between devices in order to send and receive information, which might be video, audio, or other encoded data.
Usually the signals are transmitted through wires, but they could also pass through the air via radio frequency waves.
Audio signals, for example might be transferred between your computer’s sound card and speakers, while data signals might be passed through air between a tablet and a WiFi router.
