Student Projects

arunasiddappa · ‎08-16-2011

Contact Information

University:Visvesvaraya Technological University

Team Member(s):Aruna M

Faculty Advisors:Mr Premananda BS

Email Address:arusiddhu@gmail.com, premanandabs@gmail.com

Country:INDIA

Project Information

Title:Adaptive Mobile Ring Volume For Ambient Noise

Description:

Owing to the fact that the location of the mobile phone varies from person to person or situation to situation, the impact of ambient noise has become unavoidable leading to annoying consequences like very high ringtone, missed calls etc. In order to overcome the issue cited above, the ambient noise analysis has become area of focus. Based on the ambient noise level the call alert functionality of the phone is dynamically adjusted to switch to a particular ring mode and avoid nuisance in the public areas.

Products:

Goldwave Digital audio editor tool, audacity, Wave surfer, Beagle board

The Challenge:

The challenge is to analyze different background noise types and to set appropriate gain which determines the ring volume

The Solution

Noise Analysis and Dominant Frequency Index

When an incoming call is received the captured background signal is processed using FFT which is an indicative of ambient noise, and the maximum and minimum loudness level of noise is found. The dominant frequency index which is a representative of very high noise level of the captured signal is also obtained. Depending on the maximum and minimum noise level, the tuning factor for ring volume in responsive to ambient noise level is derived.

Different types of noise are considered, which are captured at a sampling rate of 8 KHz using 16 bit PCM format. Analysis of these noise as well as ringtone is made using GoldWave digital audio editor tool, which captures, samples, play etc. of the audio signal. Visuals (figure 1, 2a, 2b, 3a, 3b, 4) display the ringtone sound, different types of noise and the modified ringtone captured in main window of Goldwave. X axis represents the time in seconds (5 seconds) and y axis the amplitude of sampled signal.

Figure 1 represents the original ringtone which has to be modified for different noisy environment. Figure 2 a represent the white noise and figure 2 b is the output amplified ringtone obtained which can mask white noise, similarly figure 3 a, 3 b for Jet type of noise, and figure 4 represents the diminished ringtone for silent condition or when there is no noise.

Simulation Results on Gold Wave

Figure 2 represents the white noise which has a maximum loudness of 72 dB, which is an indicative of the averaged loudness level of first 16 sub frames (1024 samples) with dominant frequencies index of 0, 6, 20, 11, 30, and 21. The noise level is initially very high and gradually reduces. Hence, we should derive the gain factor for the ringtone shown in figure 1 in such a way that, it amplifies the ringtone initially and then reduce its level analogous to the varying white noise. By trial and error method the gain factor for which satisfactory results were obtained is found to be 8.334, but this value may change depending on the user perception level, type of noise and also on the specifications of microphone. Similarly for jet noise the maximum and minimum loudness level of noise were found to be 66 and 56 dB, same procedure is followed and satisfactory results were obtained for the gain factor of 9. Figure 2a, 3a shows the modified ring volume analogous to varying noise levels.

From the figures 2a, 3a linearity in output transition can be seen i.e. there is no sudden transition from low to high or vice versa which is undesirable in audio processing. Figure 4 shows the ringtone with very less volume approximately with loudness level of half the original ringtone (figure 1) because there is no noise or measured noise level is less than 10 dB. Table 1 represents different loudness levels of noise calculated for White and Jet noise types along with their dominant frequencies index. N_L represents the measured noise loudness in dB.

Table 1: Noise Loudness levels

White Noise Levels (fig 4.2)							Jet Noise Levels (fig 4.3)
N_L (dB)	Dominant Frequencies Index						N_L (dB)	Dominant Frequencies Index
71	14	1	7	3	24	12	56	8	12	7	9	11	10
72	0	6	20	11	30	21	65	8	12	13	9	10	11
70	0	16	13	30	17	21	64	8	12	13	9	10	11
71	22	9	17	23	15	25	64	12	13	8	9	10	11
71	15	1	10	11	9	5	64	12	13	8	9	10	11
70	18	6	26	3	14	8	66	13	12	8	10	9	11
70	12	6	14	13	23	17	64	12	8	13	9	10	11
70	7	30	2	12	23	20	63	12	13	11	9	8	10
68	0	1	2	10	21	5	60	12	8	9	13	11	10
69	0	13	23	21	10	5	64	13	12	10	9	8	11
68	0	6	31	15	10	12	61	13	12	8	10	9	11
69	0	24	14	13	7	31	60	12	13	9	8	10	11
68	0	1	14	3	22	23	57	11	13	10	8	9	12
68	0	10	22	7	4	20	65	13	12	8	9	10	11
67	0	10	17	14	12	24	66	12	13	8	10	9	11
68	0	1	29	11	8	7	66	12	8	13	9	10	11
67	0	6	7	21	12	5	63	8	12	13	10	9	11
67	10	12	23	19	4	7	66	13	12	9	8	11	10
66	0	11	6	15	29	5	64	12	8	13	9	10	11
65	13	16	14	11	7	5	66	12	8	13	10	9	11
65	15	20	7	25	8	5	62	12	13	8	10	9	11
65	7	10	11	24	4	19	58	12	13	8	11	9	10
64	13	12	20	16	4	5	66	8	12	9	13	10	11
64	31	13	29	12	4	5	65	12	13	8	9	10	11
63	0	27	19	9	11	10	62	9	8	13	12	11	10
63	0	7	6	14	17	12	62	12	8	13	10	9	11
62	0	24	9	15	4	5	64	8	9	12	13	10	11
61	0	8	22	13	6	18	60	10	13	9	8	11	12
60	0	1	8	14	4	17	57	12	13	8	9	10	11
60	25	15	7	29	28	10	60	13	12	9	8	10	11
59	0	22	7	15	9	11	61	8	12	9	13	11	10
57	0	22	9	10	27	21	65	13	12	10	9	8	11
56	0	6	9	12	29	15	62	12	7	8	10	9	11
54	0	10	19	23	14	5	63	11	12	13	8	9	10
54	27	24	13	3	29	23	65	13	12	8	11	9	10
51	9	16	10	22	13	20	64	13	12	8	9	10	11
48	20	13	9	7	23	5	64	9	8	12	10	13	11
43	19	1	2	18	10	5	63	12	10	13	8	9	11
34	0	1	2	16	9	7	63	8	9	13	12	10	11

jcallaway · ‎09-16-2011

Hey Aruna,

Thank you so much for your project submission into the NI LabVIEW Student Design Competition. It's great to see your enthusiasm for NI LabVIEW! Make sure you share your project URL with your peers and faculty so you can collect votes ("likes") for your project and win. Collecting the most "likes" gives you the opportunity to win cash prizes for your project submission. If you or your friends have any questions about how to go about "voting" for your project, tell them to read this brief document (https://forums.ni.com/t5/Student-Projects/How-to-Vote-for-LabVIEW-Student-Design-Projects-doc/ta-p/3...).

Good luck,

Jessica in Austin, Texas

LPS · ‎10-19-2011

Hey guys,

Thanks for your submission. If your team is interested in getting certified in LabVIEW, we are offering students who participate in our Global NI LabVIEW Student Design Competition the opportunity to achieve certification at a fraction of the cost. It's a great opportunity to test your skills and enhance your resume at the same time.

Thanks and good luck in our competition!!

Liz