# NNS_SndPlayerSetTrackModSpeed

## C Specification

      #include <nnsys/snd.h>

      void NNS_SndPlayerSetTrackModSpeed(
      NNSSndHandle*   handle,
      u16 trackBitMask,
      int speed );

## Arguments

`handle` | The sound handle pointer.
`trackBitMask` | This is the track bit mask.
`speed` | Modulation speed value. Takes a value between 0 and 255.

## Return Values

None.

## Description

This function changes the modulation speed for the sequence track.

The track modulation speed of the sequence that is bound to the Sound Handle is changed. This function does not perform any action if the stream handle is invalid.

`trackBitMask` specifies the track to be set. The tracks are identified from the lower bit in sequence: Track 0, Track 1, Track 2 .... All tracks that have enabled bits will have their modulation speed changed. For example, to change the modulation speed of Track 2 and Track 5, use (1 << 2) | (1 << 5) , i.e., 0x0024.

The default value for speed is 0, which corresponds to about 6.4 Hz. When the value doubles in size, the frequency also doubles.

### Note

If a modulation speed value is already set inside the sequence data, the value set later is the one that is valid.

## See Also

None.

## Revision History

06/01/2004 Revised to state that the Sound Handle binds to the sequence.

04/01/2004 Initial version.