Question 3

Discuss with drawing on how the mechanism of the human ear protects the ear from

loud sound.

(5 marks)

The DVD sampling rate is 176.4 kHz, and 20 bits coding are employed to record 500

minutes of two channel stereo uncompressed musical song where each song is 5 minutes

duration with interval of 10 seconds separation. Execute the calculation to analyse the

number of DVD required to store the songs, assuming a DVD size is 4.7 GB.

(5 marks)

(b)

SINGAPORE UNIVERSITY OF SOCIAL SCIENCES (SUSS)

MTD205

(i)

MIDI protocol is used to demonstrate the application of audio technology in

multimedia. A set of MIDI subroutines is being attached below. They can be used in a

C-language program to control MIDI device. The subroutine parameters can be

specified in the MIDI specification in Appendix I and all parameter values must be in

hexadecimal format. Please use the subroutines to do the following operations.

(ii)

(iii)

(iv)

(v)

Page 3 of

midi_note(pitch,channel,velocity)

midi_cmd(message_type dataBytel dataByte2)

pause (delay Time) [in milliseconds]

System Active Sensing

Tutor-Marked Assignment

(3 marks)

System Start and select song number 20 at starting point at a count of 500

(3 marks)

Channel 12 plays Middle C note for 5000 ms at middle volume and then

maximum volume.

(3 marks)

Channel 15 plays note at 880 Hz for 7000 ms at middle volume and then quarter

volume by following the formula to obtain pitch value which is given as P = 69

+ 12log (f/440).

(3 marks)

Channel 14 plays note at 440 Hz for 8200 ms at middle loudness and then total

silent by following the formula to obtain pitch value which is given as P =69 +

12log (f/440).

(3 marks)