Importance of pitch perception

Question 1

Why is pitch important?

Answer 1

• most sources of sound involve object vibrating
  -regular vibration produces sound waves that repeat over time
• perceive repeating sound waves as pitch (fundamental frequency)
  -variation in fundamental frequency of vowel sounds in speech can be used to convey info
• Allow us to separate different sounds occurring at the same time
• pitch of voice provides cues to age + sex of talker

Question 2

What is a pure tone?

Answer 2

• Has a single frequency.
  -200HZ = vibrates 200 times a second

Question 3

what is a harmonic complex tone?

Answer 3

• set of pure tones
• Have frequencies that are multiples of the frequency of the lowest tone
  -200, 400,600,800 Hz
• first harmonic / fundamental frequency = tone with the lowest frequency
• most perceive the harmonic complex tone as fundamental frequency

Question 4

What determines the pitch of a harmonic complex tone?

Answer 4

• ohm + Hermon vol Helmholtz believed the pitch is determined by hearing the fundamental frequency
• However, they are both wrong

Question 5

What happens it we remove the first harmonic?

Answer 5

-even when first harmonic is removed, can still hear pitch + melody
- perception of pitch doesn’t require an audible first harmonic

Question 6

what happens if we mask the first harmonic with noise?

Answer 6

• even when the 1 St is masked can still hear pitch + melody

Question 7

what determines the pitch of a harmonic complex tone

Answer 7

• Because frequencies are multiples of the fundamental frequency
• Brain can work out the fundamental frequency even when you present a harmonic complex tone without first few frequencies

Question 8

Communication over the telephone

Answer 8

-Telephones only transmit a limited range of frequencies (300-3000)
- Average male = 100, female = 200
- difference in , pitch is major cue that distinguishes men from female voice so we can still perceive pitch

Question 9

separating simultaneous voices:

Answer 9

• Another use of pitch
• enables Listeners to separate perceptually the voices of 2 talkers who are speaking at the same time
• Accuracy is greater when fundamental frequency of target voice differs from competing voice
  -large difference allows better accuracy
• Accuracy lower when fundamental frequency of target + competing voice are multiples