In recent years, with Hearing aid With the development of electro-acoustic technology, deaf patients who were considered unsuitable to wear hearing aids in the past may also be equipped with suitable performance Hearing aid It can also be said that deaf patients who wish to improve their verbal communication skills, as long as they have residual hearing, can be selected as hearing aids.For patients, hearing aids are their ears, which play an important role. Choosing a good hearing aid requires not only scientific selection and professional fitting, but also the cooperation of patients.People think that the sound quality of expensive hearing aids is better. In fact, there are too many factors that affect the sound quality of hearing aids. So what are the general reasons for the sound quality of hearing aids?
XNUMX. Is the sound quality related to the hearing aid effect?
The sound quality is the sound quality, which reflects the objective technical level of the sound output of the hearing aid, and at the same time integrates some subjective listening experience of the user.The so-called “high sound quality” means that the sound must be processed with “high fidelity”. Only “high fidelity” can ensure high definition. It can be said that the sound quality determines the hearing aid effect, and the sound quality determines the quality of the hearing aid.
XNUMX. What factors affect the sound quality of hearing aids?
1. Hearing aid background noise:Background noise has a great impact on users with better hearing or some frequencies. Some high-end hearing aids have a background noise as low as 14dB.At the same time, it is necessary to distinguish the difference between ambient noise and background noise. For example, some high-end hearing aids have a compression threshold as low as 20 dB, and the low-level amplification is sufficient, but normal people will sound very noisy and feel it is noise.
2. The frequency response range of hearing aids:我们知道正常人耳可听见的频率范围：20Hz-20KHz，言语的频率范围：200Hz-8KHz。助听器频响越宽越不容易感觉喇叭声，声音也就越自然越逼真，有些高档的唯听助听器输出频响曲线可以达到7000Hz。
3. Compression technology:Is fast compression better or slow compression better?Both fast and slow compression have their own advantages. Generally speaking, slow compression technology is more conducive to the best linear restoration of the language. The language signal has strong contrast and high definition. However, in some specific occasions, fast compression must be used.
Now some high-end hearing aids are also doing well in this regard.
4. Non-linear distortion of hearing aids:Including distortion caused by digital processing technology, distortion caused by nonlinear amplification and distortion caused by certain noise reduction processing.Adopting “high sampling rate” analog-to-digital conversion can reduce the distortion of hearing aid sound; “high-bit” analog-to-digital conversion can reduce the distortion caused by loud input.
5. The response speed of hearing aids:The slow response speed causes the sound to sound soft, not strong, the sound is weak, and it is easy to produce echo.People with better bone conduction or low frequency have this feeling more obvious.Generally speaking, the low frequency response speed of sound is slower than the higher frequency response speed.Therefore, some hearing aid users with good low-frequency hearing and poor high-frequency are more likely to feel the feeling of echo, which causes the sound to sound unclean and unclear.