# Overview of the Voice Message service parameters

Some Natural Access functions have parameters that you can modify to:

- Enable or disable function features.

- Adapt a function for exceptional configurations.

For example, when recording speech data you can specify:

- The subset of DTMF keys entered by the telephone caller that abort the function.

- The gain applied to the input signal.

- An initial timeout in which the caller must start speaking before the function terminates.

- The amount of silence after a caller has stopped speaking before the function terminates.

- The beep tone frequency, amplitude, and duration.

- Automatic gain control settings.

These parameters are grouped together into structures for convenience and efficiency. Each parameter structure has a default value that is sufficient for many configurations.