摘要:

In this experiment, sound‐pressure levels of the noise in a diving chamber, which was pressurized to a depth equal to 100 ft of sea water, were measured. In the first of two dives, measurements were taken during compression and decompression with a piezoelectric microphone oriented so that it was approximately in a horizontal line with the diver's ear and facing away from the vent. In the second dive, the microphone was at the same position in the chamber, but hanging downward at the diver's ear level. The microphone was previously calibrated under pressure using a reciprocity calibration technique. Measurements were taken with an octave‐band noise analyzer located outside the chamber. The results indicate that the noise levels were highest in the frequency range between 300 and 4800 Hz. Hyperbaric noise levels are discussed in relationship to recently proposed damage risk criteria for exposure to noise.

ISSN:0001-4966    

DOI:10.1121/1.1912983

出版商:Acoustical Society of America    

年代:1972

数据来源: AIP

摘要:

Masking‐level differences (MLDs) of substantial magnitudes were found in forward and backward masking situations. Their magnitude diminishes exponentially as the silent interval between signal and masker increases. Implications of the data for current models relating to the MLD are suggested.

ISSN:0001-4966    

DOI:10.1121/1.1912984

出版商:Acoustical Society of America    

年代:1972

数据来源: AIP

摘要:

The amplitude of cochlear‐microphonic responses in cats was attenuated up to 18 dB during both induction and recovery from nitrous oxide anesthesia, with smaller changes (up to 3 dB) occurring during the periods of maintained anesthesia. This response variability was clearly related to alterations of middle‐ear pressure and could not be attributed to changes in middle‐ear muscle or efferent olivocochlear bundle activities. Middle‐ear pressure rose during inhalation of nitrous oxide with periodic abrupt returns to baseline levels during the period of maintained anesthesia; pressure became negative after withdrawal of nitrous oxide.

ISSN:0001-4966    

DOI:10.1121/1.1912985

出版商:Acoustical Society of America    

年代:1972

数据来源: AIP

摘要:

Sorting is a quick and reliable procedure for rank ordering stimuli along a subjective continuum. However, sorting auditory stimuli is difficult because they cannot be physically handled. This difficulty was overcome with a computer by assigning numbers to stimuli stored digitally on a random‐access disk. Subjects ordered the stimuli by rearranging the order of the numbers in a displayed list. Only a few subjects were necessary to obtain reliable results with the ordering procedure in several speech evaluation experiments.

ISSN:0001-4966    

DOI:10.1121/1.1912986

出版商:Acoustical Society of America    

年代:1972

数据来源: AIP

摘要:

Single motor unit muscle action potentials were recorded from various locations within the speech musculature using bipolar hooked‐wire electrodes with 1 mm of separation between electrode tips. Initial attempts at characterization of the waveforms are described.

ISSN:0001-4966    

DOI:10.1121/1.1912987

出版商:Acoustical Society of America    

年代:1972

数据来源: AIP