Overtone focusing in biphonic tuvan throat singing.

Khoomei is a unique singing style originating from the republic of Tuva in central Asia. Singers produce two pitches simultaneously: a booming low-frequency rumble alongside a hovering high-pitched whistle-like tone. The biomechanics of this biphonation are not well-understood.

Spectrotemporal Modulation Sensitivity as a Predictor of Speech-Reception Performance in Noise With Hearing Aids.

The audiogram predicts <30% of the variance in speech-reception thresholds (SRTs) for hearing-impaired (HI) listeners fitted with individualized frequency-dependent gain. The remaining variance could reflect suprathreshold distortion in the auditory pathways or nonauditory factors such as cognitive processing. The relationship between a measure of suprathreshold auditory function-spectrotemporal modulation (STM) sensitivity-and SRTs in noise was examined for 154 HI listeners fitted with individualized frequency-specific gain.

Having Two Ears Facilitates the Perceptual Separation of Concurrent Talkers for Bilateral and Single-Sided Deaf Cochlear Implantees.

Objectives: Listening to speech with multiple competing talkers requires the perceptual separation of the target voice from the interfering background. Normal-hearing listeners are able to take advantage of perceived differences in the spatial locations of competing sound sources to facilitate this process. Previous research suggests that bilateral (BI) cochlear-implant (CI) listeners cannot do so, and it is unknown whether single-sided deaf (SSD) CI users (one acoustic and one CI ear) have this ability.

Cochlear implantation leading to successful stapedectomy in the contralateral only-hearing ear.

Cochlear implants have recently begun to be offered to patients with single-sided deafness (SSD). Implantation in these patients has led to good results in suppressing ipsilateral tinnitus and in providing audiologic benefits in terms of speech perception in noise and localization. One previously unreported benefit of cochlear implantation in patients with SSD is the restoration of functional hearing in the previously deaf ear, which may allow for surgical opportunities in the contralateral hearing ear.

Release from informational masking in a monaural competing-speech task with vocoded copies of the maskers presented contralaterally.

Single-sided deafness prevents access to the binaural cues that help normal-hearing listeners extract target speech from competing voices. Little is known about how listeners with one normal-hearing ear might benefit from access to severely degraded audio signals that preserve only envelope information in the second ear. This study investigated whether vocoded masker-envelope information presented to one ear could improve performance for normal-hearing listeners in a multi-talker speech-identification task presented to the other ear.

Trimodal speech perception: how residual acoustic hearing supplements cochlear-implant consonant recognition in the presence of visual cues.

Objectives: As cochlear implant (CI) acceptance increases and candidacy criteria are expanded, these devices are increasingly recommended for individuals with less than profound hearing loss. As a result, many individuals who receive a CI also retain acoustic hearing, often in the low frequencies, in the nonimplanted ear (i.e.

An initial experience of cochlear implantation for patients with single-sided deafness after prior osseointegrated hearing device.

Objective: To compare preoperative and postoperative sound localization and surgical outcomes in patients with a history of osseointegrated hearing device (OHD) placement who underwent cochlear implantation for severe to profound sensorineural hearing loss in one ear and normal cochlear function in the contralateral ear (single-sided deafness [SSD]).

Study Design: Case series.

Study Setting: Tertiary care center, cochlear implant (CI) program.

Spectrotemporal modulation sensitivity for hearing-impaired listeners: dependence on carrier center frequency and the relationship to speech intelligibility.

Poor speech understanding in noise by hearing-impaired (HI) listeners is only partly explained by elevated audiometric thresholds. Suprathreshold-processing impairments such as reduced temporal or spectral resolution or temporal fine-structure (TFS) processing ability might also contribute. Although speech contains dynamic combinations of temporal and spectral modulation and TFS content, these capabilities are often treated separately.

Auditory models of suprathreshold distortion and speech intelligibility in persons with impaired hearing.

Background: Hearing-impaired (HI) individuals with similar ages and audiograms often demonstrate substantial differences in speech-reception performance in noise. Traditional models of speech intelligibility focus primarily on average performance for a given audiogram, failing to account for differences between listeners with similar audiograms. Improved prediction accuracy might be achieved by simulating differences in the distortion that speech may undergo when processed through an impaired ear.

Spectrotemporal modulation sensitivity as a predictor of speech intelligibility for hearing-impaired listeners.

Background: A model that can accurately predict speech intelligibility for a given hearing-impaired (HI) listener would be an important tool for hearing-aid fitting or hearing-aid algorithm development. Existing speech-intelligibility models do not incorporate variability in suprathreshold deficits that are not well predicted by classical audiometric measures. One possible approach to the incorporation of such deficits is to base intelligibility predictions on sensitivity to simultaneously spectrally and temporally modulated signals.

Set-size procedures for controlling variations in speech-reception performance with a fluctuating masker.

Adaptive signal-to-noise ratio (SNR) tracking is often used to measure speech reception in noise. Because SNR varies with performance using this method, data interpretation can be confounded when measuring an SNR-dependent effect such as the fluctuating-masker benefit (FMB) (the intelligibility improvement afforded by brief dips in the masker level). One way to overcome this confound, and allow FMB comparisons across listener groups with different stationary-noise performance, is to adjust the response set size to equalize performance across groups at a fixed SNR.

Effects of spectral smearing and temporal fine-structure distortion on the fluctuating-masker benefit for speech at a fixed signal-to-noise ratio.

Normal-hearing listeners receive less benefit from momentary dips in the level of a fluctuating masker for speech processed to degrade spectral detail or temporal fine structure (TFS) than for unprocessed speech. This has been interpreted as evidence that the magnitude of the fluctuating-masker benefit (FMB) reflects the ability to resolve spectral detail and TFS. However, the FMB for degraded speech is typically measured at a higher signal-to-noise ratio (SNR) to yield performance similar to normal speech for the baseline (stationary-noise) condition.

Auditory and auditory-visual intelligibility of speech in fluctuating maskers for normal-hearing and hearing-impaired listeners.

Speech intelligibility for audio-alone and audiovisual (AV) sentences was estimated as a function of signal-to-noise ratio (SNR) for a female target talker presented in a stationary noise, an interfering male talker, or a speech-modulated noise background, for eight hearing-impaired (HI) and five normal-hearing (NH) listeners. At the 50% keywords-correct performance level, HI listeners showed 7-12 dB less fluctuating-masker benefit (FMB) than NH listeners, consistent with previous results. Both groups showed significantly more FMB under AV than audio-alone conditions.

Harmonic segregation through mistuning can improve fundamental frequency discrimination.

This study investigated the relationship between harmonic frequency resolution and fundamental frequency (f(0)) discrimination. Consistent with earlier studies, f(0) discrimination of a diotic bandpass-filtered harmonic complex deteriorated sharply as the f(0) decreased to the point where only harmonics above the tenth were presented. However, when the odd harmonics were mistuned by 3%, performance improved dramatically, such that performance nearly equaled that found with only even harmonics present.

The relationship between frequency selectivity and pitch discrimination: sensorineural hearing loss.

This study tested the relationship between frequency selectivity and the minimum spacing between harmonics necessary for accurate fo discrimination. Fundamental frequency difference limens (fo DLs) were measured for ten listeners with moderate sensorineural hearing loss (SNHL) and three normal-hearing listeners for sine- and random-phase harmonic complexes, bandpass filtered between 1500 and 3500 Hz, with fo's ranging from 75 to 500 Hz (or higher). All listeners showed a transition between small (good) fo DLs at high fo's and large (poor) fo DLs at low fo's, although the fo at which this transition occurred (fo,tr) varied across listeners.

The relationship between frequency selectivity and pitch discrimination: effects of stimulus level.

Three experiments tested the hypothesis that fundamental frequency (fo) discrimination depends on the resolvability of harmonics within a tone complex. Fundamental frequency difference limens (fo DLs) were measured for random-phase harmonic complexes with eight fo's between 75 and 400 Hz, bandpass filtered between 1.5 and 3.

Detection and F0 discrimination of harmonic complex tones in the presence of competing tones or noise.

Normal-hearing listeners' ability to "hear out" the pitch of a target harmonic complex tone (HCT) was tested with simultaneous HCT or noise maskers, all bandpass-filtered into the same spectral region (1200-3600 Hz). Target-to-masker ratios (TMRs) necessary to discriminate fixed fundamental-frequency (F0) differences were measured for target F0s between 100 and 400 Hz. At high F0s (400 Hz), asynchronous gating of masker and signal, presenting the masker in a different F0 range, and reducing the F0 rove of the masker, all resulted in improved performance.

An autocorrelation model with place dependence to account for the effect of harmonic number on fundamental frequency discrimination.

Fundamental frequency (f0) difference limens (DLs) were measured as a function of f0 for sine- and random-phase harmonic complexes, bandpass filtered with 3-dB cutoff frequencies of 2.5 and 3.5 kHz (low region) or 5 and 7 kHz (high region), and presented at an average 15 dB sensation level (approximately 48 dB SPL) per component in a wideband background noise.

Correct tonotopic representation is necessary for complex pitch perception.

The ability to extract a pitch from complex harmonic sounds, such as human speech, animal vocalizations, and musical instruments, is a fundamental attribute of hearing. Some theories of pitch rely on the frequency-to-place mapping, or tonotopy, in the inner ear (cochlea), but most current models are based solely on the relative timing of spikes in the auditory nerve. So far, it has proved to be difficult to distinguish between these two possible representations, primarily because temporal and place information usually covary in the cochlea.

Pitch discrimination of diotic and dichotic tone complexes: harmonic resolvability or harmonic number?

Three experiments investigated the relationship between harmonic number, harmonic resolvability, and the perception of harmonic complexes. Complexes with successive equal-amplitude sine- or random-phase harmonic components of a 100- or 200-Hz fundamental frequency (f0) were presented dichotically, with even and odd components to opposite ears, or diotically, with all harmonics presented to both ears. Experiment 1 measured performance in discriminating a 3.