辅导 LIN328 Basic Acoustics and Acoustic Filters辅导 C/C++程序

LIN328 Reading Guide 1

Reading: Chapter 1: Basic Acoustics and Acoustic Filters

Notes:

1. On quizzes, you will not be expected to do any math that is more complicated than multiplying or dividing by 1000. You can leave any other values as fractions.

2. Make sure to always label your axes on graphs, and include units (e.g. ms, Hz). You do not need to provide units for axes representing amplitude unless specifically requested.

3. When you turn in reading guides, you do NOT need to turn in your answers to the vocabulary items, only the exercises. However, you should make sure you know the vocabulary items for the quizzes.

4. When asked to draw waveforms/spectra/etc., you can do it in any way you’d like: using the Draw function in Word, drawing with a stylus on a tablet, or drawing on paper and taking a picture. However, keep in mind that for quizzes you will need to be able to draw these by hand!

Vocabulary:

· sound wave

· (acoustic) waveform.

· periodic vs. aperiodic sounds

· simple periodic waves (sine waves) vs. complex periodic waves

· period

· frequency, amplitude, phase

· (power) spectrum

· filters: low-pass, high-pass

Concepts:

1. In phonetics, we almost always refer to times in milliseconds (ms), but Praat measures times in seconds (s).

Convert to milliseconds:

a. 1 second

b. 0.2 seconds

c. 0.054 seconds

Convert to seconds:

d. 3000 ms

e. 1210 ms

f. 5 ms

2. What is the frequency (rounded to the nearest Hertz) if the period of a sine wave is:

a. 0.01 seconds

b. 10 ms

c. 0.33 seconds

d. 33 ms

3. Draw two waveforms with the same frequency but different amplitudes. Then draw two waveforms with the same amplitude but different frequencies. Make sure to label the x-axis. You can label the y-axis “amplitude.” You can use the empty grid below (copy it 4 times for the 4 separate graphs) or draw your own.