Speech audiometry, or speech testing, is a set of tests to check how well someone can hear and understand speech. It involves presenting phonemes, spoken words, phrases, or sentences at varying volume levels (intensity). This helps to evaluate a person's auditory threshold, speech recognition ability, and overall auditory processing capabilities.
When is speech audiometry performed?
Following conventional pure tone audiometry, an audiologist will perform speech audiometry. This helps us understand how well someone can hear and can add to further information following tone audiometry.
Speech audiometry can help to identify problems with the ear, cochlea, auditory nerve, brainstem, or the brain's auditory centers. This evaluates how well someone can hear and understand speech:
Reception
Reception refers to the level at which the patient can hear whether speech is present. The patient only needs to hear the sound and respond to its presence. They do not have to identify what the sound is (similar to tone audiometry).
Discrimination
Discrimination refers to the level at which the patient can discriminate between different words. For example, the audiologist may ask the patient to respond only when they hear a specific word. E.g. ‘cat’ with several similar sounding words presented such as ‘bat’, ‘hat’ and ‘mat’ etc.
Recognition
Recognition refers to the level at which the patient can recognise and recall a word. For example, we will present young children with a selection of items that sound similar. Paediatrics will ask the child to point to the correct item.
If the stimulus is ‘key’ the patient will need to correctly point to or touch the ‘key’. There may also be a ‘tree’ toy as an acoustic pair for this test (McCormick Toy Test).1
Speech Recognition Threshold (SRT)
Speech Recognition Threshold (SRT) is a test used to determine the softest or lowest level a person can detect or recognise speech.
A comprehensive hearing evaluation typically measures SRT in decibels hearing level (dB HL), which is an important component.
A person must correctly repeat 50% of the speech material, typically involving numbers or spondaic words. SRT testing shows how well the subject can hear speech and helps with other tests like Word Recognition (WR) tests. This enables the appropriate starting points for further evaluations.
Speech Detection Threshold (SDT)
The speech detection threshold (SDT) is the level at which speech is audible to a person. This is the lowest volume someone can correctly repeat or understand a set of standard words or balanced word lists. For example, words like baseball, hotdog, etc.
SDT is important for checking hearing through air conduction audiometry and should closely match the pure tone average (PTA). Typically, PTA is calculated by averaging the thresholds obtained at 500, 1000, and 2000 Hz. A difference between the PTA and SDT of ±6 dB is good, ±7 to 12 dB is adequate, while ±13 dB or more is poor.
Advanced speech testing
The signal-to-noise ratio (SNR) determines this. The SNR measures the level of the speech signal compared to the level of background noise. The higher the SNR, the easier it is for the patient to hear and understand speech.
Performing speech testing in the presence of noise elevates the amount of neurological processing required to perform the task. The subject will need to separate the information they want (target speech) from what they don’t want (noise). This assesses how well the subject can perform auditory processing.
Advanced speech testing considers factors such as the location of the speech in relation to background noise. It also takes into account the differences in tone between the speech and masking signals. These factors are important in determining the accuracy of the speech test results.
Industry-leading audiometers
Speech audiometry is an essential component of hearing evaluations and can provide valuable information for diagnosing hearing loss. This helps decide the best treatment (such as hearing aids or cochlear implants) and check if the treatments are working.
The Model 270+ two-channel diagnostic audiometer comes with enhanced technology for a more accurate and efficient testing experience. SRT and SDT can be easily defined at the most comfortable volume level (MCL), using recorded and live speech tests. Providing fast and efficient hearing aid fitting.
The Model 260 is a cost-effective, portable and dependable diagnostic audiometer. The device includes recorded and live speech testing functionality. In addition to free field output (clinical tests such as Stenger and ABLB).
The Model 270 two-channel diagnostic audiometer also provides an extensive range of measurements - including speech testing.
For more information about our diagnostic audiometers, visit our audiometers webpage. Or contact our customer support team on +44 (0)1865 880 846 or email.
References
1National Library of Medicine, The IHR-McCormick Automated Toy Discrimination test (Aug 1989). Accessed at: https://pubmed.ncbi.nlm.nih.gov/2790310/