Recording questions (Yu-Hsiang Wu )


Subject: Recording questions
From:    Yu-Hsiang Wu  <yu-hsiang-wu@xxxxxxxx>
Date:    Fri, 14 Jan 2011 18:55:08 -0500
List-Archive:<http://lists.mcgill.ca/scripts/wa.exe?LIST=AUDITORY>

Dear List, I am trying to record real-world sounds for hearing aid testing and am wondering if anyone can help me out. Specifically, I used a manikin (KEMAR) and the G.R.A.S. RA0045 ear simulator to record street noises. The recorded sound will be presented to subjects in the lab via earphones. My goal is to accurately replicate the sound (especially in sound level) so that the listener is seemingly placed on the street. These are what I did. 1. Record the street sound (let’s call this sound is Input A) using the KEMAR and the RA0045. The KEMAR’s ears are not occluded. The recorded sound is called Output A. 2. Process Output A (e.g., filtering). Let’s call the processed Output A as Input B. 3. Present Input B to the KEMAR through earphones (Sennheiser IE 8 ear- canal headphones), which are inserted into KEMAR’s ears. Record the sound using the same RA0045. The recorded sound is Output B. 4. Compare Output B to Output A. Repeat steps 2 and 3 until a filter bank that makes Output A and Output B have the same level and spectrum is found. 5. Use this filter bank to process Output A and present it to subjects. I think these procedures could make earphones transparent because the coupler microphone generates the same output for sounds from the street and for sounds from the earphone. However, when I was listening to the processed sound through the earphones (step 5), my perception was that the sound delivered from the earphones was louder than the sound that I heard on the street. Any comments? Thanks in advance. Yu-Hsiang Wu University of Iowa


This message came from the mail archive
/home/empire6/dpwe/public_html/postings/2011/
maintained by:
DAn Ellis <dpwe@ee.columbia.edu>
Electrical Engineering Dept., Columbia University