1 Loudness and Pitch Be sure to complete the loudness and pitch interactive tutorial at … chophysics/pitch/loudnesspitch.html chophysics/pitch/loudnesspitch.html

2 Loudness Subjective correlate of intensity Normally use terms such as soft, comfortable, loud, softer, or louder, etc.

3 Scales Sone Scale Phon Scale

4 Sone scale Used to measure the growth of loudness. Based on a 40 dB SL, 1000 Hz reference When a sound is twice as loud it is two sones, when it is four times louder than the reference it is four sones, etc. In normal hearing people two sones is equal to about a 10 dB increase (50 dB SL). Every doubling of loudness yields an additional 10 dB SL in intensity increase.

5 Example of Sone Scale

6 Phon Scale Based on concept of equal loudness contours Used to measure loudness across frequencies.

7 Example of Phon Scale

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9 Pitch Subjective correlate of frequency Normally use terms such as low pitch, high pitch, lower and higher pitch, etc.

10 Mel Scale 40 dB SL 1000 Hz as a reference mels = 1000 Hz Subjects are required to match increases in frequency with increases in pitch. Research has shown that frequency rises at a higher rate than pitch. What are the implications?

11 Growth of pitch

12 Mechanisms used to determine pitch Determining pitch for periodic signals. We use the fundamental frequency (fo). We use the largest multiple of a group of component frequencies to determine fundamental. Remember, that the lowest frequency does not always equal the fundamental. e.g., if the component frequencies are 500, 550, 600 Hz, the fo is 50 Hz.

13 Mechanisms used to determine pitch Determining pitch for aperiodic signals. We use the center frequency. E.g., a narrow band noise with a center frequency of 1000 Hz would have the same pitch as a pure tone of 1000 Hz, or a periodic signal with a fo of 1000 Hz.

14 Summary