Decibels

Audiqueen offers a wide range of psychoacoustic tests, each with its appropriate dB test scale. A quick overview of each dB test scale in Audiqueen is given below:

• dB SPL: decibel Sound pressure level
• dB HL: decibel Hearing level. Used in, among other tests, tonal audiometry where each frequency has a specific RETSPL value.
• dB HL*: This intensity scale indicates that a subjective loudness balancing between the test stimuli was performed with normal-hearing individuals, referenced to a 1kHz Narrow Band Noise at 70 dB HL. Hence, it represents a scale with equal loudness at 70 dB HL. This scale is mainly used in A§E phoneme detection, phoneme discrimination, and phoneme identification tests.
• dB HL!: decibel hearing level for speech signals. In general, this is defined as the intensity level where normal-hearing individuals can recognize 50% of the speech material. Note that, by definition, hearing level RETSPL values are test-specific.  The exclamation mark is used to indicate that the professional should be aware of the fact that this scale depends on the individual settings in Audiqueen and does not necessarily correspond to a dB HL scale as defined by ISO or other physical standards.

Tonal audiometry

This test is presented in dB HL. For supported audiometers like Aurical and Affinity, the internal RETSPL conversion tables of the audiometer itself are used. 

Loudness scaling

This test is presented in dB HL. For each Narrow Band Noise sound, centered at 250, 1000, and 4000 Hz, the 1991 ASHA RETSPL values for a monoaural sound field at 0 degrees are used (table 1).

1991 ASHA RETSPL values for a monaural sound field at 0 degrees.

Phoneme discrimination and identification

The test below is presented in a dB HL* scale. All stimuli were loudness balanced in reference to a 1kHz narrow band noise at 70 dB HL in normal hearing adults. For this test, it is common practice to test at 70 dB HL*. 

When a phoneme pair is played at an intensity different than 70 dB HL*, 
it will be displayed inside the score box     

Just-noticeable-difference test (JND)

All JND tests (harmonic intonation, disharmonic intonation, sentence intonation,…) are presented on a dB SPL scale. The preferred intensity level of these tests is 70 dB SPL.

Localization test

Both azimuth and ILD localization are presented in a dB SPL scale. The default intensity to perform these tests is 70 dB SPL.

Phoneme detection

This is presented in a dB HL* scale. All speech sounds are loudness balanced in reference to a 1kHz narrow band noise near threshold level (25 dB HL) in normal hearing adults.

Speech and speech in noise audiometry test

We believe it is good practice to present speech signals in dB SPL. The reason for this is that Audiqueen offers the possibility to have multiple speech tests, which can have slightly different RETSPL values depending on the language and difficulty of the test.

See also: Should I use dB HL for speech audiometry?

However, should you prefer to test on an HL scale, Audiqueen offers the possibility to present speech signals in dB HL!, with a custom RETSPL value to be set.

The user can create a dB HL! scale for speech testing with a custom RETSPL value.