Sound Data Representation Simulator

Sampling controls

Sample rate8,000 Hz

Bit depth8-bit

Teaching presets

Wave display

Display length (ms)

Start time (s)

Source & playback

Wave source

Frequency extension

Error display

File-size calculation

Channels

Duration (s)

Unit base

Visual key

Original waveform model

Measured sample points

Quantised sample values

Magnified quantisation error

Important: the smooth blue waveform is a teaching model of the original analogue signal. A computer stores discrete numerical sample values, not a continuous curve.

Digital Audio Sampling Observe how sample rate and bit depth change the representation

LIVE MODEL

Sample rate

8,000 Hz

samples each second

Sampling interval

—

time between samples

Quantisation levels

—

2 raised to bit depth

Bit rate

—

uncompressed PCM data rate

File size

—

Waveform · samples · quantised values Change sample rate to alter horizontal spacing; change bit depth to alter vertical precision.

Original Samples Quantised

Quantisation error · magnified Lower bit depth → larger rounding difference between measured and stored amplitude

Ready to compare the original and quantised sound.

Use a low bit depth first to make quantisation error both visible and audible.

Representation process

From sound wave to stored data

Analogue signalAmplitude changes continuously with time.

→

SamplingAmplitude measured at regular time intervals.

→

QuantisationEach measurement rounded to one available level.

Stored result: each quantised sample value can be represented in binary using the selected number of bits.

What the controls change

Sample rate 8,000 / second

More samples per second gives more frequent measurements of the waveform.

Bit depth 256 levels

More bits provide more possible amplitude values and reduce quantisation error.

Current comparison Increase sample rate to make the sample points closer together. Reduce bit depth to make the red steps and yellow error easier to see.

File-size calculation

For uncompressed PCM audio, file size depends on sample rate, bit depth, channels and duration.

bit rate = sample rate × bit depth × channels
size (bits) = bit rate × duration
size (bytes) = size (bits) ÷ 8

Current calculation —

Frequency extension

The Nyquist sampling theorem is an optional extension for showing why sample rate also limits the highest frequency that can be represented without aliasing.

Accuracy & scope

Teaching model: the display separates sampling and quantisation so both effects are visible. Real digital audio stores numerical sample values; the red sample-and-hold line is a visual aid, not a claim that digital-to-analogue conversion literally outputs square steps. The file-size calculation represents uncompressed PCM-style data and excludes container/header metadata and compression.