soundsc

Scale data and play as sound

Syntax

soundsc(y)

soundsc(y,Fs)

soundsc(y,Fs,nBits)

soundsc(___,yRange)

Description

soundsc(y) scales the values of audio signal y to fit in the range from –1.0 to 1.0, and then sends the data to the speaker at the default sample rate of 8192 hertz. By first scaling the data, soundsc plays the audio as loudly as possible without clipping. The mean of the dynamic range of the data is set to zero.

soundsc(y,Fs) sends audio signal y to the speaker at sample rate Fs.

soundsc(y,Fs,nBits) uses nBits bits per sample for audio signal y.

soundsc(___,yRange), where yRange is a vector of the form [low,high], linearly scales the values in y between low and high to the full sound range [-1.0,1.0]. Values outside [low,high] scale beyond [-1.0,1.0]. You can use yRange with any of the input arguments in the previous syntaxes.

Examples

Play Sample Data at Default Sample Rate

Load the example file gong.mat, which contains sample data y and rate Fs, and listen to the audio.

load gong.mat;
soundsc(y);

Play Sample Data at Specific Sample Rate

Play an excerpt from Handel's "Hallelujah Chorus" at twice the recorded sample rate.

load handel.mat;
soundsc(y, 2*Fs);

Play Sample Data with Specific Bit Depth

load handel.mat;
nBits = 16;
soundsc(y,Fs,nBits);

MATLAB® plays the scaled audio with a bit depth of 16 bits per sample.

Scale Selected Audio Data

load handel.mat;
yRange = [-0.7,0.7];
soundsc(y,yRange);

Input Arguments

y — Audio data

column vector | m-by-2 matrix

Audio data, specified as an m-by-1 column vector for single-channel (mono) audio, or an m-by-2 matrix for stereo playback, where m is the number of audio samples. If y is an m-by-2 matrix, then the first column corresponds to the left channel, and the second column corresponds to the right channel. Stereo playback is available only if your system supports it.

Data Types: double

Fs — Sample rate

8192 (default) | positive number

Sample rate, in hertz, of audio data y, is specified as a positive number from 1000 through 384000. Valid values depend on both the sample rates permitted by MATLAB^® and the specific audio hardware on your system. MATLAB has a hard restriction of 1000 Hz <= Fs <= 384000 Hz, although further hardware-dependent restrictions apply.

Data Types: single | double

nBits — Bit depth of sample values

16 (default) | 8 | 24

Bit depth of the sample values, specified as an integer. Valid values depend on the audio hardware installed. Most platforms support bit depths of 8 bits or 16 bits.

yRange — Range of audio data to scale

[-max(abs(y)),max(abs(y))] (default) | two-element vector

Range of audio data to scale, specified as a two-element vector of the form [low,high], where low and high are the lower and upper limits of the range. Values in y that are scaled beyond [-1.0, 1.0] are clipped when played back on a sound device.

Example: [-0.8,0.8]

Data Types: double

Limitations

• soundsc ignores nBits. Instead, it plays audio data using the default number of bits per sample of the output audio device.

More About

Security Considerations When Using MATLAB Online

When using soundsc in MATLAB Online™, certain features and settings help you keep control of your privacy.

To reduce the likelihood of unwanted applications using your microphone, turn off automatic access to your audio device. You can change these settings at any time. After granting permission to a website once, your browser may be able to access your microphone automatically for that site on future visits. Use the browser settings for Google Chrome to revoke access for specific sites after you have initially allowed access.

You can also access the MATLAB Online website using the private browsing mode in Google Chrome. When you do this, Chrome™ automatically asks you for permission to access your microphone every time you open the MATLAB Online site and run soundsc, regardless of your browser settings.

Tips

• The sound function supports sound devices on all Windows^® and most UNIX^® platforms.

• Most sound cards support sample rates between 5 and 48 kilohertz. Specifying a sample rate outside this range might produce unexpected results.

• Audio playback in MATLAB Online is supported in Google Chrome™.