A Study of Acoustical Multipath Systems. Section III. Apparatus and Devices

摘要

The investigation of the effects of multiple paths on acoustic signals led to the design and development of a number of devices and associated apparatus. For use in this investigation, commercially available headphones were found to have an unsatisfactory frequency response between 20 Hz and 20 KHz. A capacitor, semi-insertion earphone (WG) was designed with a substantially flat response in this frequency range. A d.c. bias supply and binaural preamplifier (BLB-1) was obtained and modified for use with the capacitor earphone. There were no commercially available, acoustic signal pickup systems with the delay paths and frequency response characteristics of the human pinna. An artificial, binaural pinna pickup system was designed to provide a source signal for the subjective speech recognition tests. (Author)