The age (30, 40, 50, 60,70,) 

Dependant Variable: 

The sound frequency people of different ages can hear 

Sound frequency 

Control Variable: 

Sound frequency used on every age group 

How the people hear it, use same device every time 

10-20,20-30,30-40,40-50,50-60,60-70,70-80 

Dependent: Frequencies that participants can hear 

2000,4000,6000,8000,10000,12000,14000,16000,18000,20000 

Control: 

Hertz-increases by 2000 each time 

Volume&device-the sounds should be played at the same volume, from the same device 

Background sounds-the volume of background sounds must be the same each time 

The dependent variable is testing if the age affects the hearin 

Control variable one is that the sound track should be played at the same volume from the same distance for every person. This will be held the same by seating the person in the same area and not touching the volume. 

Controlled variable: 

We will use the same sound device. 

We will use the same room so the sound waves we bounce of the wall the same way each time.  

Dependent variable: The experiment will me measured in Hertz. 

Control variable one is:  

We will use the same sound device. 

It will be kept the same by: 

Choose one device for every experiment (Ipad from Haoxuan).  

Control variable two is:  

We will use the same room so the sound waves we bounce of the wall the same way each time.  

Independent variable: the age starting with 10 years with intervals of 10 until 80 years old 

Depend variable: if the person is able to hear the frequency 

The age of the people being tested 

Dependent variable:

Hearing  

Controlled variables:

• The frequency of the sound (15,000kHz)  

• The room (flat surfaces reflect the sound, but soft surfaces absorb)  

• The distance of the people towards the sound 

• Were the sound is being played 

• Windows being closed  

• Volume of the speakers 

• Same speaker  

• Same Room 

• Closed door 

• Background noise