Audio Basics: What Is Bit Depth And Sample Rate In Audio?

If you have worked in a studio, you must have wondered: “What is bit depth and sample rate in audio?”. Read this article to explore these audio principles. 

by Derrick Reeves | Updated: July 7, 2021

Are you looking for the answer to the question: What is bit depth and sample rate in audio?, what you want to know is here. Take minutes to read this article now!

These phrases have probably been familiar if you have ever produced audio with a DAW or digital recorder. They play an important role in deciding the level of detail in which sound is recorded.

Thankfully, understanding what they signify and how they operate is simple. To understand it deeper, take a look at this article.

Here is a quick explanation about bit depth and sample rate in audio: 

The sampling rate is the number of audio samples captured each second. Sample rate determines the frequency range of the recording, while the amount of amplitude values that one sample can have is determined by its bit depth.

What Is Bit Depth And Sample Rate In Audio?

bit depth and sample rate in audio

Sample rate and bit depth are phrases you've almost certainly heard before. They are crucial ideas in digital audio that have a significant impact on audio quality and sound production.

Sampling Basic

What sample rate should I use?” is a common question of those who decide to have a home recording studio or have worked with sound and music producing projects.

The sampling rate is the number of audio samples captured each second.

An audio sample is just a number that represents the acoustic wave value that was measured at a point in time. It's critical to remember that we got these samples at equidistant points in time within a second.

Assume you're going to record a one-second violin clip. There is no better audio quality than the music going directly from the instrument into your ear.

Things alter when you record the violin for subsequent replay. A microphone, which transforms them into an electrical signal, picks the sound waves coming from the violin up.

It transmits this electrical signal to your audio interface through a wire.

We convert the electrical sound wave into a sequence of data values through the audio interface's analog conversion, converting an electrical sound wave to a set of data stored in your PC.

A Sound Wave And Corresponding Sampling To Replicate The Sound

At this stage, the sampling rate becomes an important consideration.  We make up the digital audio of small samples played one after another, similar to how films are made up of visuals played in order.

The fluid motion of a minute of video recorded at a high frame rate will be significantly greater, making it look more lifelike. We use the same principle for audio.

The greater the sampling rate, the more faithfully the original analog audio waveform will be represented. It's crucial to remember that you can't change the sampling rate after recording an audio file.

Therefore, you should know your target sample rate before you start recording.

You might want to record at a faster sample rate if you know you'll be doing creative audio editing that entails extending audio files over their recorded duration (if your audio interface allows for it).

While the audio sample rate and video frame rate are comparable, the customary numerical minimum for assured usefulness in each differs significantly.

A minimum of 24 frames per second is necessary for video to ensure that motion is correctly portrayed. With any number less than that, the motion may seem choppy, and the illusion of continuous non-interrupted movement would be lost.

Since we've already discussed video frames, let's take a look at audio frames. Even though both audio samples and audio frames are measured in Hertz, they are not the same.

An audio frame is a collection of audio samples from one or more audio channels during a specific period.

Bit Depth Rate

Encoding An Analog Signal To 4-Bit Linear PCM

The amount of amplitude values that one sample can have is determined by its bit depth. The most common type of audio in PCs is pulse-code modulation (PCM).

We quantize the sampled signal's amplitude to the nearest value within a specified range. The bit depth determines the number of values that may be stored within this range.

For instance, people can set the volume of a TV to the minimum amplitude or the maximum amplitude (70dB). Television only allows you to choose five distinct volume levels.

What if you wanted to adjust the loudness between the third and fourth positions? You couldn't since the amplitude resolution isn't high enough.

The television has a good amplitude resolution if you could pick from 100 distinct volume levels.

Although the amplitude range remains unchanged, you may now choose from a wider range of amplitude levels. The way bit depth works is pretty similar to that of this notion.

increasing bit depth resolution

The higher bit depth does not increase the volume of your song. A sample with a higher bit depth will have a higher resolution.

Your samples will be more accurate in replicating the analog sound source if they are correct.

Lower bit depths result in a lower signal-to-noise ratio (which you don't want in most cases), but they also result in smaller sizes. Dithering and noise shaping used at the mastering stage can minimize noise caused by exporting at lower bit depths.

However, because you must store an audio file with finite data points, there will almost certainly be some sampling imperfection known as quantization error.

 

Frequently Asked Questions 

Here are some frequently asked questions that we have collected while researching this file.

1. What are The Differences Between Audio Sample Rates And Audio Bit Depths? 

“Can human ears really figure out the distinction between 65,524 and 3,296,962,306 amplitude levels?” you might wonder.

This is a legitimate concern. Even on a 16-bit machine, the noise level is quite low. 16-bit is suitable for the final bounce of a project unless you require over 96 dB.

However, working with a greater audio bit depth on a project is not a terrible idea. Because the noise floor falls, you have greater room before deformation begins (referred to as headroom).

Having this extra buffer area before deformation is a nice safeguard and gives you more freedom when working.

2. Is A Higher Audio Sample Rate Better? 

In music and audio production software, higher sample rates of 88.2 kHz, 96 kHz, and even 192 kHz are available. Is there a benefit to using these greater sample rates?

Choosing higher sample rates can have certain benefits if you have the tools and skills to appropriately manage any conversions.

Most musicians we know use sample rates of 44.1 kHz or 48 kHz. When converting higher sample rate material back to 44.1 kHz, you can avoid fold-back aliasing difficulties.

3. What Sample Rate Should We Use? 

44.1 kHz is the optimal sample rate to use for most music applications. When making music or other audio for video, we commonly use 48 kHz.

Although higher sample rates have advantages in professional music and audio production, many professionals still work at 44.1 kHz. Higher sample rates can have drawbacks, and they are more appropriate in professional settings.

4. What Bit Depth Should We Use? 

A 16-bit bit depth is totally fine for consumer or end-user applications. A bit depth of 24 bits is preferable for professional applications such as mixing, mastering, video editing, and recording.

This ensures a wide dynamic range and greater editing precision. Professional programs may benefit from a 32-bit floating-point bit depth.

However, the files require up to 50% more space than 24-bit audio files.

5. How Do We Choose The Suitable Sampling Rate And Bit Depth  For Audio?

That said, if there are no frequency components in an analog signal greater than a particular frequency, you may recreate the raw analog signal by sampling it twice.

You must be certain that the analog signal you are sampling has no components greater than 22 kHz.

The audible range that humans can hear refers to as bit depth. The human ear can detect sound amplitudes ranging from 0 to 130 dB SPL loud that can seriously damage your hearing.

Therefore, we should flawlessly reproduce any audio with typical CD quality.

Conclusion

It's clear how fortunate we are to live in this age of audio engineering that we have a better understanding of what is bit depth and sample rate in audio. We can manipulate audio with digital audio, many of which were impossible with analog systems.

Advances in technology have helped address many of the issues in a digital system throughout time. As technology advances, digital audio will eventually be completely indistinguishable from its analog equivalent.

crossmenu