This application relates to hearing assistance devices, and more particularly, to real ear measurement (REM) systems for hearing assistance devices.
Hearing assistance devices are electronic devices that provide signal processing functions such as noise reduction, amplification, and tone control. In many hearing assistance devices these and other functions can be programmed to fit the requirements of individual users. Performance of a user's hearing assistance device, while the device is in the user's ear, is difficult to measure. The expense of measurement equipment, the time it takes to make the measurements, and the perceived complexity of the procedure, have all proven to be obstacles to widespread use of such measurements. However, such measurements may enable better programming of a user's hearing assistance device because each user's ear is different. There is a need in the art for improved systems to assist in measuring the performance of a hearing assistance device while the device is in the user's ear.
The present subject matter provides apparatus and methods for real ear measurements of hearing assistance devices disposed in the ear of a user. Examples are provided, such as an apparatus including a thin tube for detecting sounds near the user's ear canal with an occluding portion of the hearing assistance device inserted in the user's ear. The thin tube includes a coupler for connecting the tube to the hearing assistance device. In other examples, a stretchable band of material is included for blocking ports about the housing of the hearing assistance device such that interference from such ports reaching the thin tube microphone is attenuated so as not to interfere with the measurement.
The present subject matter also provides methods of making real ear measurements. An example of the method is provided and includes a first procedure of generating a tonal complex signal, analyzing the signal in the frequency domain, applying gains based on pre-stored coupler response data, synthesizing the signal in the frequency domain, presenting the signal to the user's ear canal using the receiver of a hearing assistance device, capturing the sound near the user's ear drum using, for example, a first end of a thin tube, analyzing the signal received from a microphone of the hearing assistance device located near the second end of the thin tube, monitoring the signal against limits related to user comfort and output performance of the receiver, and comparing the captured response with a desired response to derive gains that compensate for the shape and volume of the user's ear canal. The second portion of the example procedure includes generating a tonal complex signal, applying the gains from the first portion of the procedure, presenting the signal to the user's ear canal, collecting several samples of the signal near the user's ear drum, analyzing the signal for a bad sample, collecting a number of good samples and averaging the samples to provide an accurate model of the user's real ear response.
This Summary is an overview of some of the teachings of the present application and is not intended to be an exclusive or exhaustive treatment of the present subject matter. Further details about the present subject matter are found in the detailed description. The scope of the present invention is defined by the appended claims and their equivalents.
The following detailed description refers to subject matter in the accompanying drawings which show, by way of illustration, specific aspects and embodiments in which the present subject matter may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the present subject matter. References to “an”, “one”, or “various” embodiments in this disclosure are not necessarily to the same embodiment, and such references contemplate more than one embodiment. The following detailed description is, therefore, not to be taken in a limiting sense, and the scope is defined only by the appended claims, along with the full scope of legal equivalents to which such claims are entitled.
In the illustrated example, the earhook 104 accommodates a receiver enclosed in the hearing assistance device housing. In various embodiments, the earhook accommodates wired or wireless receivers located remotely from the hearing assistance device housing. The illustrated earhook of
The sound tube plug 101 attaches to the earhook 104 using the sound tube receptacle 110. In the illustrated example, the plug 101 is pressed into the receptacle 110 such that the recess 102 of the plug 101 mates with the raised profile 111 of the receptacle 110. As the plug 101 presses into the receptacle 110, the plug material compresses to pass through the restricted opening of the receptacle slot. After the plug 101 fully enters the slot, the plug material relaxes and expands to fill the receptacle 110 thus forming a sound-tight connection. The open portion of the receptacle 110, allows verification of the connection in that the user can verify the end of the plug is flush with the face of the hearing assistance device housing. The open portion of the receptacle 110 also allows the user to observe the mating of the sound tube plug recess 102 with the corresponding raised profile 111 of the sound tube receptacle 110.
In some embodiments, the hearing assistance device is in communication with a programmer. The programmer sends a command to initiate a fitting procedure. In other embodiments, a programmer is not connected and the fitting procedure is initiated using the controls of the hearing assistance device. In examples where the hearing assistance device has multiple microphones, only the sound tube microphone is active for the fitting procedure. In examples where the hearing assistance device has multiple input sound openings, some openings are occluded to minimize reception anomalies of the active microphone resulting from multiple sound paths. A microphone opening may be occluded as in
In various examples, a periodic signal 350 is injected into the device during the fitting procedure, converted into the frequency domain by analysis block 351 and amplified 352 by gains 359 calculated to achieve a desired level 358. In other examples, the fitting procedure advances using the hearing assistance device generate the periodic signal. Varying tones of different frequencies are used as the periodic signal 350. These tones are selected to assist in providing a sinusoidal signal of interest to map the transfer function of the listener's actual inner ear canal with the hearing aid in position. In various embodiments, tones are selected at 100 Hertz intervals. The uncomfortable level (UCL) and receiver saturation 357 are monitored to assure the receiver transmits the signal at a level comfortable to the user and within the linear operating of the receiver. In various embodiments, UCL parameters are pre-stored in the hearing assistance electronics and are customized to the user. The resulting amplified tones are converted back into the time domain by synthesis block 353 and played to the receiver 354. The tones played by receiver 354 are picked up by the sound tube in the ear canal and received by the sound tube microphone 355. The gain of the system is thus adjusted to the desired levels for frequency regions of interest.
After the gains are established, the system can perform the process of
The process is repeated several times for each desired frequency such that a statistically accurate representation of the user's real ear response is obtained using the stored data. The use of periodic sinusoidal tones allows the processes to provide a shorter analysis and determination of real ear response as compared to analysis of random or white noise stimuli. In various embodiments, the analysis and capture of samples of real ear measurements is completed in 2.5 to 5 seconds depending on the number of rejected samples, the total samples collected and transducer sensitivity. The use of periodic, sinusoidal tones also provides resistance to biases introduced to the saved data by background noise.
After the fitting procedure measures the response of the user's ear, the response is processed with the pre-stored coupler response to produce the real-ear coupler difference (RECD). The RECD is stored in the memory of the hearing assistance device. The thin tube is removed as the RECD and the stored electro acoustical behavior of the hearing assistance device is used to provide accurate data of the actual response of the user's ear. A programmer in communication with the hearing assistance device can display data received from the hearing assistance device. Such data accurately indicates the input to and the output of the actual hearing assistance device while in the ear of the actual user, instead of an approximation based on average RECDs and average coupler responses. Such information can be used to provide additional diagnoses and/or treatment of the user.
This application is intended to cover adaptations or variations of the present subject matter. It is to be understood that the above description is intended to be illustrative, and not restrictive. The scope of the present subject matter should be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled.
The present application is a divisional of U.S. patent application Ser. No. 12/102,602, filed Apr. 14, 2008 which claims the benefit of priority under 35 U.S.C. §119(e) to U.S. Provisional Application No. 60/912,343, filed Apr. 17, 2007, both of which are incorporated herein by reference in their entirety.
Number | Date | Country | |
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60912343 | Apr 2007 | US |
Number | Date | Country | |
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Parent | 12102602 | Apr 2008 | US |
Child | 13902135 | US |