Install jaaa by entering the following commands in the terminal:
sudo apt update sudo apt install jaaa
Description:
audio signal generator and spectrum analyser
Jaaa (JACK and ALSA Audio Analyser) is an audio signal generator and spectrum analyser designed to make accurate measurements. . Jaaa allows you select on of the four inputs, 'Min' and 'Max' the min and max displayed frequencies. There can be up to two markers which helps accurately read off values in the display.
Homepage: http://kokkinizita.linuxaudio.org/linuxaudio/index.html#jaaa
Version: 0.8.4-4
Section: universe/sound