Word in noise test

Choosing the right hearing aid isn’t always easy. Not only do many patients have budget constraints that limit them to a certain price spectrum, but different patients have different types of hearing loss. 

To reduce the guesswork and match patients with the best hearing aids for their hearing loss, audiologists conduct a variety of hearing tests. Basic pure-tone hearing tests are still the gold standard in fitting hearing aids (like our online hearing test), yet now, speech hearing tests that simulate real-world noise conditions – called speech-in-noise (SIN) testing – are adding even more detail to existing  hearing assessment methodologies.

Below, we’ll help you understand what speech-in-noise testing entails, how it works, and how it can provide more detail to a normal hearing loss assessment.

Why Should You Consider Speech-in-Noise Testing?

The first complaint most hearing loss patients report is the inability to understand voices in noisy environments. Therefore, it makes sense that hearing loss evaluations should simulate listening to speech in noise – as SIN testing does – to evaluate your comprehension abilities in these situations.

Moreover, a survey of patients with hearing aids revealed that the most common problems patients encounter with their hearing aids is poor performance in noisy environments. Here’s what the survey found about hearing aid performance in noise: 

• 14% of hearing aid users were not happy with the performance of their hearing aids in noise. 
• 11% of hearing aid users “loved” the performance of their hearing aids in noise. 
• 75% of hearing aid users said they were somewhere between “loving” and “being dissatisfied with” their hearing aids in noise.

All in all, these points make a strong case for why you should request a speech-in-noise (SIN) test for the most accurate assessment of your hearing loss possible.

What Does SIN Testing Tell Your Audiologist?

SIN tests simulate a wide variety of real-world speech-in-noise listening conditions. This provides your audiologist or hearing care provider with detailed insights into your condition, not only to select an appropriate hearing aid but also to achieve the most effective fine-tuning of your hearing aid. 

Here are the kinds of questions SIN testing can answer for your audiologist:

• Do you need a hearing aid with directional microphones?
• Do you need the most powerful noise reduction technology?
• Do you need a hearing aid with “signal processing” to reduce background noise distractions?
• Do you need any of these features at all?

If you’re lucky, the fourth question will apply to you – and SIN testing will reveal that you don’t need any expensive bells and whistles on your hearing aid, and the most inexpensive solution will suffice. On the other hand, if you do need advanced hearing aid features, SIN testing will help your audiologist pinpoint exactly what kind of hearing aid to select, and what kinds of results you can expect from using the device. 

By evaluating these factors, the SIN test provides patients and audiologists with the insights they need for the best hearing aid selection and fine-tuning. That way, patients are more likely to use their hearing aids and receive the benefits they’re looking for – instead of simply putting their hearing aids aside.  

Types of SIN Tests

There are a variety of speech-in-noise tests that audiologists use to evaluate hearing. These include:

• Hearing in Noise Test (HINT): The HINT plays pre-recorded statements with key words in them that the test taker needs to identify and understand. 
• Words in Noise (WIN): The WIN is a test distributed by the VA. It plays different monosyllabic words that must be identified in different simulated background noise conditions. 
• QuickSIN: The QuickSIN can be obtained through Etymotic Research. It’s a sentence-based listening test for adults where recordings are played in different simulated background noise conditions.
• Bamford-Kowal-Bench SIN (BKB-SIN): This test is similar to QuickSIN, but it is appropriate for both adults and children. 
• Connected Speech Test (CST): This test is given in paragraph form, sentence by sentence, under a selected fixed background noise level. The test determines the ability to hear and comprehend connected speech.
• Speech Perception in Noise Test (SPIN): This test evaluates the ability to hear sentences under a selected fixed background noise level.

Hearing Loss Isn’t Always in the Ears

Your ability to understand speech in noise isn’t always about your ears. While your ears’ ability to hear voices clearly is essential to understanding speech, your brain also needs to process the language for complete comprehension. Some patients compensate for hearing loss with highly-developed speech processing skills. If they miss a few words, their brains can still interpret the gist of what people are saying. 

A hearing loss patient could be suffering from ear damage, a central auditory nervous system disorder, cognitive decline – or all of the above. 

• Are you suffering from cognitive decline?
• Are you suffering from ear damage? 
• Are you suffering from a central auditory nervous system disorder?
• Are you suffering from all or just one of the above?

Imagine that your SIN test reveals that no hearing assistance techniques are able to help you overcome your hearing loss challenges. Your hearing care provider can then refer you to a medical practitioner for cognition testing to ensure that you aren’t suffering cognitive decline. The sooner you know, the sooner you can treat the right problem to improve your hearing.

Ask Your Audiologist About SIN Testing for the Most Accurate Hearing test

SIN testing simulates real-world background noise conditions, requires you to listen to and try to understand voices in noise, and it can be used to test your hearing while you try different types of hearing assistance. 

Considering the superiority of SIN testing, you should ask your hearing care provider for SIN (speech-in-noise) testing before selecting a hearing aid. This will ensure that you don’t waste money on a hearing solution that isn’t going to work, and it will help you fine-tune your hearing aid effectively. Ultimately, getting SIN testing can make you happier with the performance of your hearing aid in the long run. 

MDHearing: Send Your Hearing Tests Results to Our Audiologists!

At MDHearing, we recommend that you visit a hearing clinic or audiologist for a professional hearing exam before choosing one of our products. We also recommend that you ask for SIN testing to ensure you get the most accurate hearing test results.

Then you can send your test results to the audiologist team at MDHearing. We’ll review your test results and recommend which MDHearing product is best for your needs.

Shop MDHearing Products

At MDHearing, we sell high-quality, FDA-registered hearing aids for thousands of dollars less than comparable brands. Priced between $399.99 and $1,199.99 per pair, MDHearings products also come with a 100% money-back guarantee, so there’s no risk in giving them a try.

After ordering your hearing aid from MDHearing, you’ll receive it in just a few days. Our on-call hearing aid specialists can walk you through the process of adjusting and fine-tuning your hearing aid to fit your hearing loss profile. 

Here are three of our most popular hearing aids:

• MDHearing AIR: Priced at just $399.99 per pair, the AIR features advanced digital technology, feedback cancellation, and settings for four listening environments (quiet, social, noisy, and restaurant). 
• MDHearing VOLT: Priced at just $599.99 per pair, the VOLT is our rechargeable model that features intelligent directional microphones, feedback cancellation, and background noise management technology to clarify sounds in four different listening environments. 
• MDHearing CORE: Priced at just $1,199.99 per pair, the CORE offers Bluetooth connectivity and a smartphone app for easy fine-tuning and adjustments. It also features intelligent directional microphones, feedback cancellation, and background noise management technology to clarify important sounds and voices in four listening environments.

To learn more about MDHearing and its catalog of affordable, high-quality digital hearing aids, browse our website now.
BROWSE HEARING AIDS

By Douglas L. Beck and Lauren Benitez

This article is a part of the May/June 2019, Volume 31, Number 3,  Audiology Today issue.

Hearing-care professionals (HCPs) and hearing aid wearers report the chief complaint secondary to hearing loss and to wearing traditional hearing aids, is the inability to understand speech-in-noise (SIN; see Beck et al, 2019). Beck et al (2018) reported that, in addition to the 37 million Americans with audiometric hearing loss, 26 million have hearing difficulty and/or difficulty understanding SIN, despite clinically normal thresholds. As such, helping people hear (i.e., to perceive sound) and helping people listen (i.e., to comprehend, or apply meaning to sound) remains paramount.

Many excellent SIN tests are commercially available (see Wilson et al, 2007 for a review). Nonetheless, despite the fact that the American Academy of Audiology (Academy) and the American Speech–Language–Hearing Association (ASHA) Best Practice (BP) statements recommend SIN testing, it appears that fewer than 15 percent of audiologists perform SIN tests routinely (Beck, 2017; Clark, 2017). It is unclear why SIN testing is not applied universally. Perhaps the associated acquisition costs, the negligible reimbursement rates, and/or the administration time impede their clinical use?

Regardless, we believe a SIN score acquired on an individual, regardless of his or her audiogram, represents the single most important measure of auditory function. Unaided and aided SIN scores not only reflect the reason the patient sought help (i.e., the unaided SIN score) but also indicate how much help he or she has received through amplification (i.e., the aided SIN score). In this article, we will outline a SIN protocol that may be free or relatively inexpensive (depending on the equipment you already own, and the cost of calibration).

Our SIN protocol takes less than 120 seconds to administer and is quick, reliable, and clinically useful. In addition, we will present pilot data acquired on eight individuals with and without audiometric hearing loss, and we will offer some calibration guidelines (Appendix).

Background

Jerger (2018) recently reviewed two important articles from the 1940s. The Harvard Report (1946) indicated monosyllabic word testing has “rather low reliability” even when carefully standardized. The Harvard Report suggested that measuring the signal-to-noise ratio (SNR, the level difference required for speech to be comprehended in a background of noise) was an intriguing idea. Jerger reflected favorably on The Harvard Report for indicating that an SNR measure would be a better metric reflecting individual differences in challenging acoustic environments. Carhart (1946) also indicated clear benefits associated with obtaining an SNR measure to reflect speech understanding in difficult noisy situations.

An individual’s SIN performance cannot be reliably predicted from his or her speech-in-quiet (SIQ) performance. That is, knowing that a person has excellent word recognition in quiet using monosyllabic words (such as the NU-6, or the CID W-22 word lists) simply does not indicate how the individual will perform in speech babble.

Wilson (2011) evaluated 3,430 veterans and reported SIN scores cannot be predicted based on an audiogram, and word recognition in quiet does not predict SIN ability. Therefore, the audiologist should establish/quantify the degree of SIN impairment (as indicated by the SNR-50, see below). Of note, a group of individuals with mild–moderate sensorineural hearing loss (SNHL) is likely to have a broad range of SIN abilities, which interestingly, may be analogous to the range of people with normal pure-tone thresholds (Vermiglio et al, 2012; Vermiglio et al, 2019).

Improving SIN ability generally is accomplished through an improved SNR. Indeed, familiar technologies including adaptive and nonadaptive directional microphones, beam-forming microphones, and various adaptive and nonadaptive noise-reduction protocols and algorithms have been incorporated into hearing aids to essentially improve the SNR, thereby improving the wearer’s SIN ability.

SNR-50

The SNR required to obtain a score of 50 percent correct is referred to (throughout this article) as the “SNR-50.” Of note, establishing the SNR-50 (in this protocol) is very similar to obtaining a pure-tone threshold. The primary speech signal is held constant at the most comfortable loudness (MCL) while four-talker speech babble ascends and descends. The SNR-50 is established when the subject repeats half of the target words (50 percent) correctly. However, instead of 5- and 10-dB steps (as prescribed for pure-tone thresholds), we use 1- and 2-dB steps to rapidly acquire a repeatable SNR-50.

With regard to the QuickSIN, Killion (2002) reported adults with normal hearing needed an average SNR-50 of 2 dB to repeat 50 percent of the words correctly, and people with mild–moderate SNHL required an average SNR-50 of 8 dB. These same values offer guidance as to expected SNR-50s in this pilot study. Dillion (2012) reported that for every 10 dB of hearing loss, the subject requires an additional 1–3 dB of SNR to maintain their unaided intelligibility.

TABLE1. Pilot Program Fictitious Thresholds

SNR-50 Examples

Given a primary speech message originating in front of a listener at 70 dB SPL, a person with normal hearing and normal listening ability might be expected to repeat half the words correctly in the presence of a 68 dB four-talker babble originating behind the listener. Further, a listener with a mild–moderate SNHL, given the same speech signal of 70 dB SPL, would likely require an 8-dB SNR (babble at 62 dB SPL) to repeat 50 percent of the words correctly. To be clear, the relationship between pure-tone thresholds and SIN ability is highly variable and not predictable.

SIN and SNR-50 Pearls

#1

The anticipated SNR-50 values described here (2 dB for people with hearing within normal limits; 8 dB for people with mild-moderate SNHL) are estimates and serve as guidelines only. Each person must be tested to determine his or her SNR-50 unaided and in the sound field. Local normative values should be established for each test facility after proper calibration, to be sure results are in alignment with generally accepted values. Of note, we do not recommend using headphones or insert earphones as our goal is to replicate, as best we can, the real-world difficulty experienced in cocktail parties, restaurants, and similar acoustically challenging situations. Therefore, a  calibrated sound-field test is required.

#2

We recommend four-talker speech babble rather than speech-spectrum noise, white noise, pink noise, etc. Artificial noises do not contain linguistic information, and therefore, artificial noises may be easier to ignore. However, some people do perform better in four-talker babble rather than steady-state noise (Vermiglio et al, 2019). In general, we anticipate four-talker babble better replicates real-world difficulty; yet if the four-talker babble task is too difficult, we recommend switching to an artificial noise as needed for unaided and aided measures (apples to apples).

#3

We believe that if the primary goal of SIN testing is to determine the SNR-50, and the secondary goal is to select amplification, step sizes of 4 or 5 dB are too large to define subtle, yet important, differences in hearing aid benefit. That is, if hearing aids A, B, C, and D improve the SNR-50 by 1, 2, 3, and 4 dB, respectively, these would appear the same given a 5-dB step size. Of note, a 1-dB improvement in SNR may facilitate 8 percent to 10 percent improvement in word recognition (Taylor and Mueller, 2017), and is thus, important to quantify.

#4

Although we realize “speech in front” and “babble in rear” is not a realistic representation of all SIN tasks, this simple two-speaker arrangement can be easily facilitated in many sound booths and may also be set up outside the booth. That is, SIN tests are suprathreshold tests and may not require a sound booth (unless the ambient noise floor is excessively high) as long as the entire system is professionally calibrated for speech stimuli and four-talker babble (see Appendix). A simple, repeatable, “apples-to-apples” approach is advocated.

#5

We used the NU-6 word lists as our primary stimuli. However, all word lists are not necessarily equivalent regarding difficulty, audibility, vocabulary, and more. Some word lists have been found to be equivalent in quiet, but not in noise. As such, one should review the literature to choose the best primary stimuli (in any language) for their protocol and to establish their own clinical norms, in tandem with the protocol described here. Important readings on selecting and using words lists includes: Lawson (2012), Loven and Hawkins (1983), and Stockley and Green (2000). Regardless of the selected word lists, we recommend the use of digital recordings of your preferred word list and your own established clinical norms (as above), as hardware, software, protocols, word lists, and calibration protocols vary.

Eight adult volunteers participated in our pilot testing, with and without hearing loss. Each received otoscopy and a typical air-bone-speech evaluation. Unaided and aided sound field tests were obtained using the calibrated sound field (see Appendix). The recorded NU-6 word lists were presented through the front speaker at 70 dB SPL, and four-talker speech babble was delivered through the rear speaker. The task was explained, “Your task is to try to ignore all the voices from behind you. Please repeat the words you hear from the front speaker.”

During all SIN presentations, the front speaker loudness was held constant at 70 dB SPL, and only the rear-speaker loudness varied. Although we pre-set our front speaker to 70 dB SPL, it seems reasonable to set this to the MCL level or perhaps MCL plus 5 dB, to assure audibility (as needed), while not exceeding uncomfortable loudness (UCL) levels.

The first trial (“introductory task”) was presented with speech in the front speaker at 70 dB SPL and four-talker babble presented through the rear speaker at 55 dB SPL (15 dB SNR). This was an easy task for all participants. The introductory level allowed for a quick practice session during which we confirmed the task was understood by the listener. Of note, our protocol is similar to that used in pure-tone audiometry when bracketing thresholds. For example, using the 15 dB SNR, all participants easily got three words in a row correct.

Consequently, we reduced the SNR to 10 dB (i.e., made the babble louder by 5 dB, resulting in a 10 dB SNR), and for most people, this too, was rather easy. If the subject was only able to repeat one or two of the next three words correctly, we made the task easier by decreasing the babble by 2 dB (resulting in a 12 dB SNR) and then bracketed in 1-dB steps. The entire procedure from an introductory 15 dB SNR to their bracketed SNR-50 threshold usually involved fewer than 25 words and required less than two minutes.

In our pilot program, to avoid overamplification and uncomfortably loud presentations for people with thresholds within normal limits, we placed the following values into the Genie Software^TM, and programmed the Oticon Opn 1^TM hearing aids using the following fictitious thresholds (all were fitted with open domes, see TABLE 1).

The first test session was accomplished with the following parameters (Program 1, aka P1):

Open Sound Transition Selected by Genie, Noise Reduction Complex, Directionality OPN, Gain Control 100% (Level 3), VAC+.

The second test session was accomplished using the same parameters, except the noise reduction was reset to maximum (Program 2, aka P2).

Note: For aided presentations, before presenting the primary-speech stimulus in front, it may be important to wait 3–5 seconds (or longer) each time the four-talker babble loudness changes, to allow the noise-reduction algorithm to activate. In our pilot test, we used Oticon Opn 1^TM devices in which the noise-reduction circuit activates in less than 25 milliseconds.

Discussion

The most common complaint from people with SNHL and with traditional hearing aids is their inability to understand SIN (Beck et al, 2019). As such, obtaining a pre- and postfitting SNR-50 is important. In this article, we have demonstrated a simple protocol that can rapidly determine SIN thresholds and can be used to validate and verify important differences between unaided and aided responses. This pilot study was executed to reinforce the necessity of SIN testing and to offer a quick, inexpensive, and rational SIN protocol to help determine a patients’s unaided (baseline) and aided SIN performance, as demonstrated by their unaided and aided SNR-50.

Appendix

Equipment – MedRx Stealth or MedRx ARC with Free Field Speakers

Stimulus – NU-6 Word Lists

Babble – Auditec Speech Babble (included with all MedRx Audiometers)

Calibration – Calibrations should be performed by a trained technician with speakers at ear level. Speakers should be placed (ideally) at 0- and 180-degree azimuth at 1 meter from subject’s head. If the speakers must be moved, mark the exact location of the speakers and subject chair. Each audiometer has variable calibration protocols. MedRx audiometers must have full free-field calibrations performed for accurate speech testing. Calibration frequencies include 125–8000 Hz, white noise, speech weighted noise and speech tone.

To perform free-field calibration, the microphone location must estimate the center of the subject’s head position (marked by an X in Figure 1). All measurements should be made with the microphone in this static position. Set the sound level meter (SLM) to SPL mode (see FIGURE 2).

1. Subject and speaker diagram where X marks the calibration microphone (FIGURE 1).
2. Speakers at 0 degrees (right channel) and 180 degrees (left channel).
3. MedRx free-field calibrations (completed by certified technician).
4. Complete full pure-tone, free-field calibration using warble tones.
5. MedRx equipment must have white noise, speech babble (A Weighted), speech-tone calibrated (1000 Hz cal. tone).
6. Save calibration.

Special Thanks

The authors offer thanks and appreciation to Andy Vermiglio, AuD, and Caleb Sparkman, AuD, for their review and valuable input regarding the preparation of this manuscript. 

References

Beck DL. (2017) Best practices in hearing aid dispensing: An interview with Michael Valente, PhD. Hear Rev 24(12):39–41.

Beck DL, Danhauer JL, Abrams HB, Atcherson SR, Brown DK, Chasin M, Clark JG, De Placido C, Edwards B, Fabry DA, Flexer C, Fligor B, Frazer G, Galster JA, Gifford L, Johnson CE, Madell J, Moore DR, Roeser RJ, Saunders GH, Searchfield GD, Spankovich C, Valente M, Wolfe J. (2018) Audiologic considerations for people with normal hearing sensitivity yet hearing difficulty and/or speech-in-noise problems. Hear Rev 25(10):28–38.

Beck DL, Ng E, Jensen JJ. (2019): A scoping review 2019: OpenSound Navigator. Hear Rev 26(2):28–31.

Clark, JG, Huff C, Earl B. (2017) Clinical practice report card–Are we meeting best practice standards for adult hearing rehabilitation? Audiol Today 29(6):15–25.

Carhart R. (1946) Tests for selection of hearing aids. Laryngoscope 56(12):780–794.

Dillon H. (2012) Hearing Aids. (2d Ed) Thieme Publishers. 

The Harvard Report. (1946) Davis H, Hudgins CV, Marquis RJ, et al. The Selection of Hearing Aids. Laryngoscope 56(3):85–115.

Jerger J. (2018) Lessons from the past: Two influential articles in the early history of audiology. Hear Rev. Published Dec 5.

Killion MC. (2002) New thinking on hearing in noise: a generalized articulation index. Sem Hear 23(1):57–75.

Lawson G. (2012) Speech Audiometry, Word Recognition, and Binomial Variables: Interview with Gary Lawson. www.audiology.org/news/speech-audiometry-word-recognition-and-binomial-variables-interview-gary-lawson-phd.

Loven F, Hawkins D. (1983) Interlist equivalency of the CID W-22 word lists presented in quiet and in noise. Ear Hear 4:91–97.

Stockley KB, Green WB. (2000) Interlist equivalency of the Northwestern University auditory test No. 6 in quiet and noise with adult hearing-impaired individuals. J Am Acad Audiol 11:91–96.

Taylor B, Mueller G. (2017) Fitting and Dispensing Hearing Aids (2d ed) Plural Publishing.

Vermiglio AJ, Herring CC, Heeke P, Post CE, Fang X. (2019) Sentence recognition in steady-state speech-shaped noise versus four-talker babble. J Am Acad Audiol 30(1):54–65. 

Vermiglio AJ, Soli SD, Freed DJ, Fisher LM. (2012) The relationship between high-frequency pure-tone hearing loss, hearing in noise test (HINT) thresholds, and the articulation index. J Am Acad Audiol 23(10):779–788.

Wilson RH. (2011) Clinical experience with the words-in-noise test on 3430veterans: comparisons with pure-tone thresholds and word recognition in quiet. J Am Acad Audiol 22(7):405–423.

Speech-awareness thresholds

Speech-awareness threshold (SAT) is also known as speech-detection threshold (SDT). The objective of this measurement is to obtain the lowest level at which speech can be detected at least half the time. This test does not have patients repeat words; it requires patients to merely indicate when speech stimuli are present.

Speech materials usually used to determine this measurement are spondees. Spondaic words are 2-syllable words spoken with equal emphasis on each syllable (eg, pancake, hardware, playground). Spondees are used because they are easily understandable and contain information within each syllable sufficient to allow reasonably accurate guessing.

The SAT is especially useful for patients too young to understand or repeat words. It may be the only behavioral measurement that can be made with this population. The SAT may also be used for patients who speak another language or who have impaired language function because of neurological insult.

For patients with normal hearing or somewhat flat hearing loss, this measure is usually 10-15 dB better than the speech-recognition threshold (SRT) that requires patients to repeat presented words. For patients with sloping hearing loss, this measurement can be misleading with regard to identifying the overall degree of loss.

If a patient has normal hearing in a low frequency, the SAT will be closely related to the threshold for that frequency, and it will not indicate greater loss in higher frequencies.

Speech-recognition threshold

The speech-recognition threshold (SRT) is sometimes referred to as the speech-reception threshold.
^[2] The objective of this measure is to obtain the lowest level at which speech can be identified at least half the time.

Spondees are usually used for this measurement. Lists of spondaic words commonly used to obtain the SRT are contained within the Central Institute for the Deaf (CID) Auditory List W-1 and W-2.

In addition to determining softest levels at which patients can hear and repeat words, the SRT is also used to validate pure-tone thresholds because of high correlation between the SRT and the average of pure-tone thresholds at 500, 1000, and 2000 Hz.

In clinical practice, the SRT and 3-frequency average should be within 5-12 dB. This correlation holds true if hearing loss in the 3 measured frequencies is relatively similar. If 1 threshold within the 3 frequencies is significantly higher than the others, the SRT will usually be considerably better than the 3-frequency average. In this case, a 2-frequency average is likely to be calculated and assessed for agreement with the SRT.

Other clinical uses of the SRT include establishing the sound level to present suprathreshold measures and determining appropriate gain during hearing aid selection.

Suprathreshold word-recognition testing

The primary purpose of suprathreshold word-recognition testing is to estimate ability to understand and repeat single-syllable words presented at conversational or another suprathreshold level. This type of testing is also referred to as word-discrimination testing or speech-discrimination testing.

Initial word lists compiled for word-recognition testing were phonetically balanced (PB). This term indicated that phonetic composition of the lists was equivalent and representative of connected English discourse.

The original PB lists were created at the Harvard Psycho-Acoustic Laboratory and are referred to as the PB-50 lists. The PB-50 lists contain 50 single-syllable words in 20 lists consisting of 1000 different monosyllabic words. Several years later, the CID W-22 word lists were devised, primarily using words selected from the PB-50 lists. Another word list (devised from a grouping of 200 consonant-nucleus-consonant [CNC] words) is called the Northwestern University Test No. 6 (NU-6). Recorded tape and CD versions of all these word-recognition tests are commercially available.

The PB-50, CID W-22, and NU-6 word lists each contain 50 words that are presented at specified sensation levels. Words can be presented via tape, CD, or monitored live voice. Patients are asked to repeat words to the audiologist. Each word repeated correctly is valued at 2%, and scores are tallied as a percent-correct value.

Varying the presentation level of monosyllabic words reveals a variety of performance-intensity functions for these word lists. In general, presenting words at 25-40 dB sensation level (refer to the SRT) allows patients to achieve maximum scores. Lowering the level results in lower scores. For individuals with hearing loss, words can be presented at a comfortable loudness level or at the highest reasonable level before discomfort occurs.

When words are presented at the highest reasonable level and the word-recognition score is 80% or better, testing can be discontinued. If the score is lower than 80%, further testing at lower presentation levels is recommended. If scores at lower levels are better than those obtained at higher presentation levels, «roll over» has occurred, and these scores indicate a possible retrocochlear (or higher) site of lesion.

Another use of suprathreshold word-recognition testing is to verify speech-recognition improvements achieved by persons with hearing aids. Testing can be completed at conversational levels in the sound field without the use of hearing aids and then again with hearing aids fitted to the patient. Score differences can be used as a method to assess hearing with hearing aids and can be used as a pretest and posttest to provide a percent-improvement score

Sentence testing

To evaluate ability to hear and understand everyday speech, various tests have been developed that use sentences as test items. Sentences can provide information regarding the time domain of everyday speech and can approximate contextual characteristics of conversational speech.

Everyday sentence test

This is the first sentence test developed at the CID in the 1950s.

Clinical use of this test is limited, because its reliability as a speech-recognition test for sentences remains undemonstrated.

Synthetic-sentence identification test

The synthetic-sentence identification (SSI) test was developed in the late 1960s. SSI involves a set of 10 synthetic sentences. Sentences used in this test were constructed so that each successive group of 3 words in a sentence is itself meaningful but the entire sentence is not.

Because the sentences are deemed insufficiently challenging in quiet environments, a recommendation has been made that sentences be administered in noise at a signal-to-noise (S/N) ratio of 0 dB, which presents both sentences and noise at equal intensity level.

Speech perception in noise test

The speech perception in noise (SPIN) test is another sentence-identification test. The SPIN test was originally developed in the late 1970s and was revised in the mid 1980s.

The revised SPIN test consists of 8 lists of 50 sentences. The last word of each sentence is considered the test item. Half of listed sentences contain test items classified as having high predictability, indicating that the word is very predictable given the sentence context. The other half of listed sentences contain test items classified as having low predictability, indicating that the word is not predictable given sentence context. Recorded sentences come with a speech babble-type noise that can be presented at various S/N ratios.

Speech in noise test

The speech in noise (SIN) test, developed in the late 1990s, contains 5 sentences with 5 key words per test condition. Two signal levels (70 and 40 dB) and 4 S/N ratios are used at each level. A 4-talker babble is used as noise. This recorded test can be given to patients with hearing aids in both the unaided and aided conditions.

Results are presented as performance-intensity functions in noise. A shorter version of the SIN, the QuickSIN, was developed in 2004. The QuickSIN has been shown to be effective, particularly when verifying open-fit behind-the-ear hearing aids.

Hearing in noise test

The hearing in noise test (HINT) is designed to measure speech recognition thresholds in both quiet and noise. The test consists of 25 lists of 10 sentences and noise matched to long-term average speech.

Using an adaptive procedure, a reception threshold for sentences is obtained while noise is presented at a constant level. Results can be compared with normative data to determine the patient’s relative ability to hear in noise.

Words in noise test

The Words-in-Noise Test (WIN), developed in the early 2000s, provides an open set word-recognition task without linguistic context. The test is composed of monosyllabic words from the NU-6 word lists presented in multitalker babble. The purpose of the test is to determine the signal-to-babble (S/B) ratio in decibels for those with normal and impaired hearing. The WIN is similar to the QuickSIN in providing information about speech recognition performance.

The WIN is used to measure performance of basic auditory function when working memory and linguistic context is reduced or eliminated. This measure, by using monosyllabic words in isolation, evaluates the listener’s ability to recognize speech using acoustic cues alone and by eliminating syntactical and semantic cues founds in sentences. The WIN materials allow for the same words to be spoken by the same speaker for both speech-in-quiet and speech-in-noise data collection.

Bamford-Kowal-Bench speech in noise test

Bamford-Kowal-Bench Speech-in-Noise Test (BKB-SIN) was developed by Etymotic Research in the early to mid 2000s. The primary population for this test include children and candidates or recipients of cochlear implants.

Like the HINT, the BKB-SIN uses Americanized BKB sentences.
^[3] These words are characterized as short, and the sentences are highly redundant; they contain semantic and syntactic contextual cues developed at a first grade reading level. Compared to the HINT, which uses speech-spectrum noise, the BKB-SIN uses multitalker babble. Clinicians can expect better recognition performance on the BKB-SIN and HINT in comparison to the QuickSIN and WIN because of the additional semantic context provided by the BKB sentences.

Selecting proper speech in noise testing

QuickSIN and WIN materials are best for use in discriminating those who have hearing loss from normal hearing individuals. The BKB-SIN and HINT materials are less able to identify those with hearing loss.
^{[4, 5]} Therefore, the QuickSIN or WIN is indicated as part of the routine clinical protocol as a speech in noise task. The choice of QuickSIN or WIN is strictly a matter of clinician preference; however, the clinician must also consider whether or not the patient can handle monosyllabic words (WIN) or needs some support from sentence context (QuickSIN).

The BKB-SIN and HINT materials are easier to recognize because of the semantic content, making them excellent tools for young children or individuals with substantial hearing loss, including cochlear implant candidates and new recipients.

Most comfortable loudness level and uncomfortable loudness level

Most comfortable loudness level

The test that determines the intensity level of speech that is most comfortably loud is called the most comfortable loudness level (MCL) test.

For most patients with normal hearing, speech is most comfortable at 40-50 dB above the SRT. This sensation level is reduced for many patients who have sensorineural hearing loss (SNHL). Because of this variation, MCL can be used to help determine hearing aid gain for patients who are candidates for amplification.

MCL measurement can be obtained using cold running or continuous speech via recorded or monitored live-voice presentation. Patients are instructed to indicate when speech is perceived to be at the MCL. Initial speech levels may be presented at slightly above SRT and then progressively increased until MCL is achieved. Once MCL is achieved, a speech level is presented above initial MCL and reduced until another MCL is obtained. This bracketing technique provides average MCL.

Uncomfortable loudness level

One reason to establish uncomfortable loudness level (UCL) is to determine the upper hearing limit for speech. This level provides the maximum level at which word-recognition tests can be administered. UCL can also indicate maximum tolerable amplification.

Another reason to establish UCL is to determine the dynamic speech range. Dynamic range represents the limits of useful hearing in each ear and is computed by subtracting SRT from UCL. For many patients with SNHL, this range can be extremely limited because of recruitment or abnormal loudness perception.

UCL speech materials can be the same as for MCL. The normal ear should be able to accept hearing levels of 90-100 dB. Patients are instructed to indicate when presented speech is uncomfortably loud. Instructions are critical, since patients must allow speech above MCL before indicating discomfort.