Narrowband speech can be separated into fast temporal cues [temporal fine structure (TFS)], and slow amplitude modulations (envelope). Speech processed to contain only TFS leads to envelope recovery through cochlear filtering, which has been suggested to account for TFS-speech intelligibility for normal-hearing listeners. Hearing-impaired listeners have deficits with TFS-speech identification, ...

One of the most devastating effects of congenital hearing loss is that normal development of speech is often disrupted. As a consequence, most hearing-impaired children must be taught the speech skills that normal-hearing children readily acquire during the first few years of life. Although some hearing-impaired children develop intelligible speech, many do not. For many years, it was believed ...

Monaural phase discrimination was evaluated in normal-hearing and hearing-impaired listeners as a function of the frequency separation among components in three-tone complexes. The phases of the center components of 100% sinusoidal amplitude-modulated (SAM) waveforms were shifted by 90 degrees to yield quasi-frequency-modulated (QFM) waveforms that had identical long-term spectra but different ...

It is well known that communication in noisy environments with reverberation present is a difficult problem to solve, particularly for the hearing-impaired listener. Two-microphone noise cancelling using an LMS adaptive filter in real time was used to process speech recorded in the presence of speech-spectrum noise at six different signal-to-noise ratios, -8, -4, 0, 4, 8, and 12 dB. Twelve norm...

A novel approach to hearing-aid signal processing is described, which attempts to re-establish a normal neural representation in the sensorineural impaired auditory system. Most hearing-aid 5tting procedures are based on heuristics or some initial qualitative theory. These theories, such as loudness normalization, loudness equalization or maximal intelligibility can give vastly di(erent results...

Auditory nerve single-unit studies have demonstrated that phase-locking plays an important role in the neural encoding of the spectrum of speech-like sounds. Recently, it has been reported that the phase-locked activity underlying the scalp-recorded human frequency-following response (FFR) also encodes the first two formants of several steady-state vowels and the time-variant frequency presente...

Spectral-shape discrimination thresholds were measured in the presence and absence of noise to determine whether normal-hearing and hearing-impaired listeners rely primarily on spectral peaks in the excitation pattern when discriminating between stimuli with different spectral shapes. Standard stimuli were the sum of 2, 4, 6, 8, 10, 20, or 30 equal-amplitude tones with frequencies fixed between...

This article presents a tutorial overview of the speech-recognition difficulties of the hearing impaired. Much recent research indicates that the primary problem underlying the speech-recognition difficulties of the hearing impaired is the loss of hearing sensitivity and accompanying loudness recruitment. This tutorial demonstrates why loss of hearing sensitivity plays such an important role an...