Effects Menu

To access the Effects menu, press the Effects tab at the top of the editing window:

The menu has following options:

Auto Gain (Automatic Gain Control)

Normal recordings can have the volume of the recording too high in parts and too soft in parts. Automatic Gain Control reduces the too loud parts and increases the too soft parts. This is sometimes a better alternative to normalization.

Normalize

To 'normalize' is to adjust the volume so that the loudest peak is equal to (or a percentage of) the maximum signal that can be used in digital audio. Usually you normalize recordings to 100% as the last stage in production to make it the loudest possible without distortion.

Amplify

To 'amplify' is to increase the loudness or volume of the selected region. To make a part of the recording softer or louder, select it and then use the menu "Effects / Amplify".

Compressor (Dynamic Range Compressor)

A Dynamic Range Compressor limits the volume levels of a sound recording so that it stays within a certain loudness range.

An example of where it is used is in TV broadcasting, where it ensures that the volume levels of ads are perceived as being louder than the television program itself (without any change in the actual broadcast volume).

It also has a use for recording audio from one medium to another, where the two mediums are not capable of handling the same range of volume levels (e.g. A CD can handle a much greater range than a cassette tape).

To apply this effect, select a region then use the menu "Effects / Compressor" to bring up the Dynamic Range Compressor settings.

The Threshold setting works by detecting when the sound recording volume exceeds a defined decibel level. It then gradually attenuates the sound to bring it down below the dB level, and does it in such a way that the listener will not be aware the attenuation is occurring.

The Limit setting defines at what maximum decibel level the sound recording will be allowed to rise up to. So if, for example, the Limit was set to 0dB, then you will never hear the volume level of the recording get louder than 0dB. The Limit setting has similarities to the Threshold setting, but the main difference is that the Threshold does allow sounds to go above the defined decibel level (for a short time), whereas the Limit does not.

You will find that the minimum Limit volume you can set is the same as the maximum Threshold value. This basically means that, in any situation, the sound will start to attenuate at the threshold level, but will never be heard louder than the limit.

The Ratio setting limits the amount the volume level of the recording increases at any one time. If, for example, you wanted the volume levels of a recording to only increase by at most 1/4 of the amount they would normally increase, then this would correspond to a Ratio of 4:1. So if the recording volume level increased by 8dB, then you would only hear a 2dB volume increase.

The buttons for General Voice Level and TV / Radio Advertisement are preset settings appropriate for these types of recordings.

High Pass (High-Pass Filter)

A high-pass filter (sometimes called a low cut filter) removes all low frequencies below a specified Hz. This is useful if you want to make your recording sound 'clearer' or less 'muddy'. It is very usual to use a high-pass filter of about 300Hz on all voice recordings to improve intelligibility.

Echo

An echo is a repeat of the sound after a short time (usually 400 - 1000ms). It sounds a bit like the person is in a large stadium or is shouting between two mountains.

To add echo select the region and use the menu "Effects / Echo", then specify the duration and amplitude of the echo. The duration is the length of time after which the sound repeats - usually this is between 400 and 1000ms. The amplitude can be between 1 - 99% (99 being a very loud echo).

Reverse

This effect reverses the selection in the same way playing a record or tape backwards would.

Reverb

Reverb is an effect that applies many small refractions of the sound at a set time interval. It usually occurs when someone is speaking in a room, hall, etc. More reverb is called wet, less reverb is called dry.

Fade (Fade In, Fade Out, Fade Out and Trim)

To fade in or out the recording use the menu "Effects / Fade / Fade In" or "Effects / Fade / Fade Out".

The Fade Out and Trim option is a combined function which fades out over the selection then marks the end of the selection as the end of the recording. This is frequently used at the end of music tracks.

Silence Selection

This function silences the selected region. This function can be useful to remove breaths or clicks from a voice recording without changing the timing of the words.