The dependent variable that is being measured is the frequency and pitch of sound waves, and the ability of how well people with different ages and health can hear the sound. 

Control variable one is:  

The frequency of the sound.  

It will be kept the same by: 

For each age the same sound will be played, with the same pitch. 

Control variable two is:  

The amplitude of the sound.  

It will be kept the same by: 

For each age the same sound will  

Control variable three is:  

Testing everybody in the same place and setup.  

It will be kept the same by: 

Each person will be tested in the same room, with all the doors and windows closed, same furniture (material and in the same place). And also the having the sound being played from the same device (speakers, computers, etc) and same volume, and how far the device is to the person. The room need to be the same temperature.  

Control variable four is:  

Each participant being tested should wear the type and amount of clothing.  

It will be kept the same by:  

Each person should wear the same type and amount of clothing that does not cover their ears.  

Age of the people participating in the experiment  

The Hz (either gradually increasing or decreasing)  

Dependent variable:

The ability to hear a sound or not.  

Control variable one is: 

Sound interference   

It will be kept the same by: 

The experiment will be done ind a soundproof room, eliminating background noises and possible distractions that will affect the results. 

Control variable two is: Equipment 
 

It will be kept the same by: Using the same volume  

Control variable three is:  

The increase of sound overtime 

It will be kept the same by: 

The sound will gradually increase in Hz in the same way, ex: +1Hz added every 2 seconds. Not only will this give the participants time to try and detect the sound, but it will also not confuse the participants. 

The Dependent Variable, the Variable being measured will be which age is able to hear the best, in Hz. 

Control variable one is: the volume of sound  

It will be kept the same by: setting the volume on  a level and not changing it 

Control variable two is: same gender 

1It will be kept the same by: keeping one side of he gender without the other being in the test group 

Control variable three is: where the sound comes from 

It will be kept the same by: having the speaker or sound maker stay the same distance and angle. 

Dependent variable: What frequencies the people of different ages can hear to 

Control variable one is:  

The frcuency of the sound being used to test the experiment. 

It will be kept the same by: 

Always having the frequency the same and not changing it. 

Control variable two is:  

The size of the room. 

It will be kept the same by: 

Using the same room in every trial so that the echo is always the same. 

Control variable three is:  

The same sound every trial 

It will be kept the same by: 

Never changing the sound 

The age is getting changed to get data 

Dependent variable: the result being measured. (write in a complete sentence and include how it will be measured) 

The sounds (hertz) is getting changed 

Control variable one is: the sound 

It will be kept the same by: always playing the same sound  

Control variable two is: the same divice  

It will be kept the same by: not always using the same divice

Control variable three is: the same place (the podcast room) 

It will be kept the same by: interviewing the people in the same room( the music room)