This project shows you how to make a unit which can produce a delay of up to 8 seconds on an input audio signal.
The circuit outputs a delayed version of an input audio signal. Depending on the amount of memory implemented and the sampling rate selected, it can store from 3 seconds to 8 seconds of audio. The audio input will be delayed by an amount selectable by the user.
This device can be used to produce a delay for many purposes. Some possible applications are:
Sound effects , such as echo, can be produced by adding a delay to an input signal.
This device can produce an effect which is sometimes referred to as “Delayed Auditory Feedback”. This effect has been used to help aid those who stutter.
Another application of such a device would be in a “Speech Jammer”. Such a device records a person speaking and then plays the audio back at a delay, which causes most people to get confused and thereby disrupts their speaking. Using the device for this purpose would require a directional microphone and directional speaker.
The device can also be used to delay the audio from a television broadcast. In my research, I found that some people prefer to use a separate, radio broadcast for the play by play or commentary for sporting events, and as such they wanted to be able to introduce a delay to synchronize a separate audio source to the television broadcast.
The circuit can be used sort of like a TiVo, but for audio only. By changing the delay setting, you can go back as far back as the buffer size permints (only 8 seconds max in this design) to catch something you missed.
At any rate, the device described here can be a lot of fun to play and experiment with. The input range is controllable from 0 seconds to the maximum delay by means of an analog input. This analog input can simply be driven by a potentiometer, or from an external signal. Modulating the delay input with different waveforms can produce interesting sound effects.