The set is supplied with a velveteen case. This experiment was safety-checked in March 2020. The Brain Tuning Forks Set contains 5 unweighted forks that are designed to directly influence brain wave states. Students describe how sound from two sources can cancel out through destructive interference. The headphones include a microphone which receives sound waves from the environment and an electronic circuit generates an inverted version of these sound waves so that when this is played into the listener’s ears, the two sets of waves cancel out. The tuning fork has long been the tool of choice to help students understand the relationship between wave frequency and pitch. When the prongs move back together, they pull the air molecules and form low-pressure areas called rarefactions. As the fork’s prongs move away from each other, they push air molecules together, creating small compressions. Like the tuning forks they use destructive interference to cancel sounds. A tuning fork creates vibrations that interact with the air surrounding it. Students are likely to be familiar with noise-cancelling headphones.

If you want to draw diagrams to illustrate overlapping wavefronts use an example in which the sources are separated by a distance greater than a wavelength (eg two loudspeakers). The distance between the two prongs (a few centimetres) is smaller than the wavelength of the sound (typically a metre or so). Repeat but rotate the fork slowly about its axis while they listen. It is challenging to draw diagrams to illustrate destructive interference for a tuning fork. Strike the tuning fork on a suitable surface and hold the fork upright next to their ear. As students rotate the tuning fork, they should hear four regions of silence. The ergonomic comfort handle is easy to hold while. Sound waves from two sources can arrive in step (in phase) and constructively interfere to produce a louder sound or they can arrive out of step (out of phase) and destructively interfere. The DAddario Tuning Forks provide an extremely accurate reference pitch for tuning all instruments by ear. As they vibrate, each act as a source of sound. The tuning fork has two identical prongs.

How can two sound waves cancel each other out?.

How many sources of sound does a tuning fork have?.

Repeat but this time identify the number of times there is silence per rotation.

Presenter Brief: Understand sound waves, tuning fork motion, and vibrations. Repeat but rotate the fork slowly about its axis while they listen. Stick the tip of the vibrating tuning fork prongs into the cup of water.Strike the tuning fork on a suitable surface and hold the fork upright next to their ear.

Tuning fork waves