Pitch Shift

Kirsten HammProfessor Thomas TunksProfessor Fred OlnessMusical Acoustics ProjectDecember 5, 2013

What is the Pitch ShiftPhenomenon?According to the pitch shift phenomenon, there is a slight upward pitch-shift in human hearing as age increases.

This means that the typical non-severely damaged hearing of a child or adolescent will allow them to hear at higher frequencies than that of an

adult.• http://www.youtube.com/watch?v=3q4WduuWBws

What is the Pitch Shift Phenomenon?

The same child who can hear at high frequencies, will no longer be able to hear at those same pitches as they age. This is so because the frequencies perceived in adolescence as lower are shifted and perceived as higher as age increases. Thus the highest frequencies heard as a child are shifted out of one’s hearing range.

Mosquito RingtonesWhat are they? How do they work?Ultrasonic tones

generated by high frequency sound waves, used as ringtones

advertised especially to adolescents

Function based on pitch-shift phenomenon

Students can hear tones, but parents and older teachers cannot. (You can imagine the trouble that can bring!)

http://www.ultrasonic-ringtones.com/

If normal hearing ability is related to age, can one predict age range based on hearing ability?

Does your highest perceived pitch match your age range?

Highest Perceived Pitch (kHz) Age Range

8Above 50 yrs

10

1240's

14.1

14.9 30's

15.8 20's

16.7 about 20yrs

17.7 older teenager

18.8 younger teenager

19.9 Not yet teenager

21.1 Not human

22.4 There was no sound!

Typical Highest Frequencies Heard at Different Age Ranges

Side Note: Notice the different notes beside each frequency. Since frequency is the primary determiner of pitch, these notes/tones at which the pitches play vary related to frequency.

http://www.ultrasonic-ringtones.com/