Headphones Research Articles

INTERVENTIONS TO REDUCE HIGH‐VOLUME PORTABLE HEADSETS: “TURN DOWN THE SOUND!”

Two studies examined effects of interventions to reduce noise levels from portable stereo headphones. Study 1 examined the effectiveness of warning signs posted in and nearby public elevators with 567 passengers possessing a portable headphone (total N = 7,811). During a 9-day baseline, the mean percentage of headphones played at an observer-audible level was 85%. During a subsequent 6-day warning sign phase, the mean percentage of audible headphones declined to 59%, which increased to a mean of 76% during a second baseline phase (5 days). Study 2 assessed the impact of a student confederate who lowered his or her observer-audible headphone volume at the polite request of a second student confederate. Of the 4,069 elevator passengers, 433 possessed a portable headset. The mean percentage of observer-audible headphones during a 4-day baseline was 85%. Subsequently, a 5-day modeling intervention reduced audible volumes to a mean of 46%. During a second baseline phase of 4 days, the mean level was 77%, and during reintroduction of the modeling phase (9 days) the mean level was 42%. The modeling intervention was significantly more effective with women (53% compliance) than men (29% compliance).

Headphone cushioning

Headphone cushioning

Stereo headphone

Stereo headphone

Comparing headphone and speaker effects on simulated driving

Twelve persons drove for three hours in an automobile simulator while listening to music at sound level 63dB over stereo headphones during one session and from a dashboard speaker during another session. They were required to steer a mountain highway, maintain a certain indicated speed, shift gears, and respond to occasional hazards. Steering and speed control were dependent on visual cues. The need to shift and the hazards were indicated by sound and vibration effects. With the headphones, the driver's average reaction time for the most complex task presented—shifting gears—was about one-third second longer than with the speaker. The use of headphones did not delay the development of subjective fatigue.

Headphone comfort

Headphone comfort

The Impact of Distraction on the Processing of Category-Based and Attribute-Based Evaluations

The vulnerability of product evaluations to influence from unattended distraction material was used as an indicator of processing differences between category-based and attribute-based evaluation. Subjects listened to descriptions of products having attributes that were either high or low prototypically to the product category. Evaluatively consistent or inconsistent material was added to both the high prototypically and the low-prototypically descriptions. Subjects instructed to evaluate the products attended to these descriptions on one channel of a set of stereo headphones, while they were simultaneously exposed to either positively or negatively toned material on the unattended channel. Subjects' evaluations of products high in prototypically were not influenced by the affective quality of the unattended material, whereas evaluations of the products low in prototypically were influenced. Subjects' evaluations suggested that both category-based and attribute-based processing occurred, but to different categories in instances that were either high or low in prototypically for the product class.

Stereo headphones bracket system

Stereo headphones bracket system

Headphone cushioning

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Wireless stereo headphone

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耳鳴検査時におけるヘッドホン装着の影響

耳鳴検査時におけるヘッドホン装着の影響

Noise‐induced hearing loss in randomly selected New York dairy farmers

To understand better the effects of noise levels associated with dairy farming, we randomly selected 49 full-time dairy farmers from an established cohort. Medical and occupational histories were taken and standard audiometric testing was done. Forty-six males (94%) and three females (6%) with a mean age of 43.5 (+/- 13) years and an average of 29.4 (+/- 14) years in farming were tested. Pure Tone Average thresholds (PTA4) at 0.5, 1.0, 2.0, and 3.0 kHz plus High Frequency Average thresholds (HFA3) at 3.0, 4.0, and 6.0 kHz were calculated. Subjects with a loss of greater than or equal to 20 db in either ear were considered abnormal. Eighteen subjects (37%) had abnormal PTA4S and 32 (65%) abnormal HFA3S. The left ear was more severely affected in both groups (p less than or equal to .05, t-test). Significant associations were found between hearing loss and years worked (odds ratio 4.1, r = .53) and age (odds ratio 4.1, r = .59). No association could be found between hearing loss and measles; mumps; previous ear infections; or use of power tools, guns, motorcycles, snowmobiles, or stereo headphones. Our data suggest that among farmers, substantial hearing loss occurs especially in the high-frequency ranges. Presbycusis is an important confounding variable.

Headphone

Headphone

A spatial sound processor for headphone and loudspeaker reproduction

A spatial sound processor for stereo headphone and loudspeaker reproduction is described that can position sound elements within a three‐dimensional reverberant space surrounding the listener. Spatial motion of sound sources in three dimensions is created by dynamic filtering based on head‐related transfer functions. Additional filters and delay lines capture air absorption and Doppler shifting as the propagation time is manipulated for both direct and indirect sound. The spatiotemporal distribution of early reflections is captured for a given source/listener orientation: The gain, delay, and directional filtering of simulated reflections are responsive to changes in the specified position and orientation of the sound source and the listener's head in the simulated environment. The spatial processor can be used for headphone reproduction using a head‐tracking device, and can also be used in more typical reproduction settings such as living rooms with stereo loudspeakers. In the latter case, additional processing is employed to stabilize the stereo image and produce a spatially diffuse reverberant surround effect over a wide range of listening positions.

Stereo headphone

Stereo headphone

剣道難聴の研究

This study was planned to to compare the hearing level of Kendo-Players with that of non-Kendo-Players to make clear whether or not long term practice of Kendo causes hearing loss. Pure-tone audiometry by air conduction was applied to 172 Kendo-Players and 76 non-Kendo-Players with an audiometer (Audiometer AA-69, Audiogram Recorder RE-05, Soundproof Room AT-45, Rion, Japan). Among them, the following cases were excluded from the analysis. 1) Cases who have had medication against tuberculosis. 2) Cases with perforation in the tympanic membranes. 3) Cases with occupational experience of more than a year in noise nuisance. 4) Cases with experience of head phone listening for more than one hour a day, twice a week for at least one year. The thresholds of hearing between 149 Kendo-Players (cases, age: 19-76) and 44 non Kendo-Players (controls' age: 20_78) were analysed to compare mean hearing thresholds between the age groups, and to examine covariance adjusted with age. The dose-response relationship was examined by the partial correlation coefficients controlled by age between the thresholds of hearing and the length of Kendo experience (year) or the total experience hours of Kendo (hour). The rusults showed that the hearing loss of Kendo-players was greater than non-Kendo players, especially at the frequency of 4000 and 8000 Hz in the age group of 30-59 years old. It is supposed that long term practice of Kendo may cause hearing loss. Further study, however, will be needed to re-examine the dose-response relactionship with more carefully selected samples for the epidemiological survey in the future.

Headphone

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A technical drawing aid for blind students using stereo audio feedback

This paper describes a project to develop a technical drawing aid for blind secondary school children to assist their scientific education. The aim was to produce an accurate graph-construction system which can be used both for producing graphs and reading out existing material. The instrument comprises a conventional draughting board equipped with optical sensing of a bar track to provide digital information of co-ordinate positions. Error signals are produced in stereo headphones, and Braille tactile read-out signals are provided. Good tracking performance and acceptability have been achieved in trials with a group of blind children at Tapton Mount Blind School, Sheffield.

Modular stereo headphones

Replaceable snap-together wires, headphones, headband and plug comprise a modular stereo headphone apparatus. Sealed headphones are provided with walled receptacles to receive mating removable clips secured to the ends of connecting wires. Each clip is molded to the wire insulation and around the wire ends which protrude slightly beyond the clip. Each clip is provided with a protruding movable lever arm with an indent for mating with a protrusion inside a receptacle shaped to fit the clip. Wires from the sound system within each headphone protrude through each receptacle wall to mate in proper polarity with wires in the inserted clip. A flexible headband is provided along its length with either a groove or tabs to receive a headphone connecting wire removably secured to the headband. At each headband end a sleeve receives a protrusion from one headphone adjustably secured to the headband with a spring-loaded pin in the sleeve engaging notches in the headphone protrusion. A male plug for the sound system has an adapter with one or two receptacles for receiving one or two clip ended wires from one or two headphone sets.

Headphone

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Headphone

Headphone