Journal-Online

Home / Publications / Journal-Online

Journal of the Audio Engineering Society

>> Institutional Subscribers: View Your List of Purchased Issues

2002 April - Volume 50 Number 4

Download Entire Issue (3.78 MB)

*Only AES members and Institutional Journal Subscribers can download.

Papers

Variability in the Headphone-to-Ear-Canal Transfer Function

Authors: McAnally, Ken I.; Martin, Russell L.

Headphone-to-ear-canal transfer functions (HpTFs) for 20 headphone placements were measured for each ear of three participants and an acoustic manikin. Head-related transfer functions (HRTFs) were measured for nine sound-source locations within a 14.5~ radius of each of eight representative locations. Noises were convolved with these functions and passed through a cochlear filter model to estimate cochlear excitation. The variability of the magnitudes of the filtered HpTFs was much less than the variability of the magnitudes of the unfiltered HpTFs. It was also considerably less than the variability of the magnitudes of the filtered HRTFs. In addition, the variability of the group delays of the HpTFs for the three human participants was considerably less than the minimum discriminable interaural time difference. It follows that much of the information in HRTFs that could provide a cue to sound-source location will not be masked by the variability of HpTFs across headphone placements. The spatial fidelity of an individualized virtual audio display, therefore, will not necessarily be compromised by variability in HpTFs.

Download: PDF (46.01 KB)

Comparison of Different Impulse Response Measurement Techniques

Authors: Stan, Guy-Bart; Embrechts, Jean-Jacques; Archambeau, Dominique

The impulse response of an acoustical space or transducer is one of its most important characterizations. In order to perform the measurement of their impulse responses, four of the most suitable methods are compared: MLS (maximum-length sequence), IRS (inverse repeated sequence), time-stretched pulses, and SineSweep. These methods have already been described in the literature. Nevertheless, the choice of one of them depending on the measurement conditions is critical. Therefore an extensive comparison has been realized. This comparison was done through the implementation and realization of a complete, fast, reliable, and cheap measurement system. Finally, a conclusion for the use of each method according to the principal measurement conditions is presented. It is shown that in the presence of nonwhite noise, the MLS and IRS techniques seem to be more accurate. On the contrary, in quiet environments the logarithmic SineSweep method seems to be the most appropriate.

Download: PDF (263.63 KB)

On the Quality of Hearing One`s Own Voice

Authors: Appel, Ronald; Beerends, John G.

The way we perceive our own voice is being studied. Contrary to classical speech listening-quality experiments, where subjects judge the speech quality by listening, remaining silent themselves, in talking-quality experiments subjects judge the quality with which they perceive their own voices while actively speaking. In this way the self-listening comfort is measured. Six experiments were carried out. Five used a standard telephone setup where echo and distortions were introduced and judged by subjects on the disturbance. In one experiment subjects judged the talking quality of six different rooms. The subjective results were used to develop an objective perceptual talking-quality measure. The overall correlation between the subjectively perceived quality and the objectively measured quality was 0.97.

Download: PDF (163.26 KB)

Restoration and Enhancement of Solo Guitar Recordings Based on Sound Source Modeling

Authors: Esquef, Paulo A. A.; Välimäki, Vesa; Karjalainen, Matti

New propositions to audio restoration and enhancement based on sound source modeling are presented. A case based on the commuted waveguide synthesis algorithm for plucked-string tones is described. The main motivation is to take advantage of prior information of generative models of sound sources when restoring or enhancing musical signals.

Download: PDF (219.67 KB)